This Ground Beef & Rice Casserole is part of my One-Skillet Leftover Revival series and is an easy way to turn leftover rice into a cozy, oven-baked dinner. It starts on the stovetop with ground beef, mushrooms, and onions, then finishes in the oven with a light layer of cheese, all made in one pan for minimal cleanup.

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Recipe Overview
⏱️ Ready in: 40-45 minutes
✋ Hands-on time: 10–15 minutes
🍽️ Yields: 4 servings
🥗 Diet-friendly: Gluten-Free
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Why You’ll Love This Recipe
- A smart way to use leftover rice: Layering cooked rice over seasoned ground beef gives it new life and turns it into a cozy, satisfying casserole instead of just leftovers.
- Minimal prep, mostly hands-off: Everything starts on the stovetop and finishes in the oven, so once it’s layered, the skillet does the work.
- Comforting but not heavy: With sautéed mushrooms, onions, and just enough cheese, this dish feels rich and comforting without being too heavy.
- Great for dinner or next-day lunch: It reheats well and holds its texture, making it just as good the next day for lunch or dinner.
- Naturally gluten-free: Like my Leftover Chicken Lettuce Wraps with Beet & Cabbage Slaw recipe, this recipe is made with simple, wholesome ingredients that fit easily into a gluten-free lifestyle.
Ingredients

- Beef: Lean ground beef works well here, but you can also use veal for a slightly lighter, more delicate flavor. I used a mix of both. Make it a double leftover revival recipe and use up your leftover meat.
- Leftover rice: Leftover rice is ideal for this casserole. Cold rice holds its texture better and absorbs flavor without becoming mushy. Any cooked rice works here. Just make sure it’s fully cooked and cooled before layering.
- Mushrooms and Onion: These add depth and savory flavor. Cooking them first helps remove excess moisture and keeps the casserole from turning watery.
- Cheese: Use a good melting cheese like mozzarella, marble, or a mozzarella-cheddar blend.
- Marinara Sauce: A small amount of your favorite marinara adds richness and acidity, preventing the dish from tasting bland. I like to use it in many of my sauteed ground beef and other ground meat recipes, including my Swiss Chard Rolls and my One-Pan Buckwheat & Ground Turkey Skillet.
See the recipe card below for the full ingredient list and exact measurements.
Random Fun Facts
- Leftover rice actually absorbs flavors better than freshly cooked rice, which is why it works so well in baked dishes like casseroles.
- A small amount of tomato-based sauce can make savory dishes taste more seasoned by adding natural acidity, even without extra salt.
- Mushrooms have been used in skincare for their natural antioxidant properties and are sometimes found in face serums and masks.
Substitutions and Variations
- Ground beef: Ground beef can be swapped for ground veal, turkey, or chicken. If you're using lean meat, you may need to add a bit more olive oil when cooking.
- Marinara: Substitute with crushed tomatoes or tomato passata for a lighter tomato flavor. You may need to add a bit more salt.
- Add frozen veggies: Stir in frozen vegetable mix, like the one I use in my Shepherd's Pie with Quail Egg, when cooking the beef.
- Make it creamier: Stir a few tablespoons of sour cream or ricotta into the ground beef once it’s cooked and off the heat. You can also add a little into the onion/mushroom mixture once they are cooked.
- Make it vegetarian: Skip the ground beef and double the mushrooms, or replace the meat with cooked lentils. Keep the rest of the recipe the same for a hearty, vegetarian casserole.
- Make it spicy: Add red pepper flakes, chili flakes, or a bit of hot paprika to the beef while cooking. You can also finish the casserole with a drizzle of chili oil or hot sauce before serving.
Step-by-Step Instructions
STEP 1: Sauté mushrooms & onions

Preheat the oven to 400°F (200°C).
Heat olive oil in a large oven-safe skillet over medium heat. Add the onion and cook until softened. Add the mushrooms, season with salt, and cook until the moisture has cooked off and the mushrooms are lightly golden. Transfer to a bowl and set aside.
STEP 2: Cook the ground beef

Add the ground beef to the skillet and cook over medium heat, breaking it up. Season with salt and pepper. Cook until no longer pink. Stir in the marinara sauce and let it simmer for 1 minute. Give it a taste and adjust with additional salt or pepper. Spread the mixture evenly across the bottom of the skillet.
STEP 3: Layer the casserole

Remove the skillet from the heat.
Gently scatter the cooked rice over the beef mixture, loosening it with a fork. Top evenly with the mushroom and onion mixture, then sprinkle with cheese.
STEP 4: Bake

Transfer the skillet to the oven and bake for 15-20 minutes, or until the cheese is melted and lightly golden. If you’d like extra color on top, switch the oven to broil for the last minute.
Top Tips
- Taste the beef after adding the marinara and adjust salt and seasoning before layering. Rice will mute flavors if the base isn’t well seasoned.
- Leftover, cold, rice straight from the fridge holds its texture better and won’t turn mushy once baked.
- Make sure to brown the mushrooms well. Let the moisture cook off so they add flavor, not water, to the casserole.
- Don’t pack the layers. Simply scatter the rice instead of pressing it down to keep the casserole light.
Frequently Asked Questions
Yes. You can assemble the casserole, cover it, and refrigerate it for up to 24 hours before baking. Add a few extra minutes to the bake time if you're cooking it straight from the fridge.
Reheat gently in the oven at 350°F (175°C) until warmed through, or microwave individual portions.
Yes. Let it cool completely, then store it in an airtight container for up to 2 months. Thaw overnight in the fridge before reheating.
It’s best to sauté vegetables like mushrooms or onions first. This removes excess moisture and prevents the casserole from becoming watery.
Serving suggestions
This Ground Beef & Rice Casserole is hearty enough to serve on its own, but it pairs well with simple sides as well. Serve it alongside a fresh salad, such as this Crunchy Carrot, Cucumber & Radish Salad with Kohlrabi, some roasted vegetables, such as these Healthy Turmeric Oven Roasted Vegetables, or even a bit of Pickled Red Cabbage.
Other delicious leftover revival recipes
If you tried this Ground Beef & Rice Casserole (One-Skillet Leftover Revival) recipe or any other recipe on my website, please leave a 🌟 star rating and let me know how it went in the 📝 comments below. And feel free to tag me on Instagram @cre8athome so I can see your creations! Thanks for visiting!
Recipe

Ground Beef & Rice Casserole (One-Skillet Leftover Revival)
Equipment
- Ovenproof Skillet 12-14 inch oven-safe skillet, at least 2 - 2.5 inches deep
- Box Grater for cheese
Ingredients
- 1 tablespoon olive oil
- 1 small onion sliced
- 1 lb (450 g) mushrooms sliced - I used button mushrooms
- ¼ teaspoon salt
- 2 lbs (900 g) ground beef or ground veal, or a mix of both
- ¾ teaspoons salt
- ¼ teaspoon ground black pepper
- ½ cup marinara sauce
- 2 cups cooked rice cold leftover rice works best
- 1.5-2 cups mozzarella cheese shredded
- Fresh dill or sliced scallions for garnish
Instructions
- Preheat oven to 400°F (200°C).
- Heat olive oil in a large oven-safe skillet over medium heat.1 tablespoon olive oil
- Add onion and cook until softened. Add mushrooms, season lightly with salt and cook until the moisture evaporates and they begin to brown. Give it a taste and add more salt if needed. Transfer to a bowl and set aside.1 small onion, 1 lb (450 g) mushrooms, ¼ teaspoon salt
- In the same skillet, add ground beef. Cook over medium heat, breaking it apart as it cooks. Season with salt and pepper. Cook until no longer pink.2 lbs (900 g) ground beef, ¾ teaspoons salt, ¼ teaspoon ground black pepper
- Stir in marinara sauce, and let it simmer for 1–2 minutes. Taste and adjust with additional salt and pepper as needed.½ cup marinara sauce
- Spread the ground beef mixture evenly in the skillet and remove it from heat.
- Gently scatter cooked rice evenly over the beef mixture, loosening it with a fork. Top with the sautéed mushrooms and onions. Sprinkle shredded cheese evenly over the top.2 cups cooked rice, 1.5-2 cups mozzarella cheese
- Transfer skillet to the oven and bake for 15–20 minutes, or until cheese is melted. For extra color, switch to broil for the final 1–2 minutes, watching closely.
- Let rest for 5 minutes before serving. Garnish with fresh dill or sliced scallions.Fresh dill or sliced scallions
Notes
- Taste the beef after adding the marinara and adjust salt and seasoning before layering. Rice will mute flavors if the base isn’t well seasoned.
- Leftover, cold, rice straight from the fridge holds its texture better and won’t turn mushy once baked.
- Make sure to brown the mushrooms well. Let the moisture cook off so they add flavor, not water, to the casserole.
- Don’t pack the layers. Simply scatter the rice instead of pressing it down to keep the casserole light.









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