Mushroom Stuffed Meatloaf is savory ground beef mixed with the perfect blend of spices, mushrooms, melty cheese, and caramelized onions.
Something magical happens when you put caramelized onions and mushrooms in meatloaf with mozzarella cheese. YUM. This could also be called french onion meatloaf since the onions are cooked to golden perfection, and delicious melty cheese is also added just like in my French Onion Ground Beef Sliders.
⭐️ Why You Need This On Your Dinner Menu
- Versatile - you can use any kind of mushroom you want, or switch up the type of meat! See substitutions for types of mushrooms to use in meatloaf.
- CHEESE - if you're a cheese lover, mushroom lover, or a meat lover, this cheesy mushroom and onion meatloaf recipe is for you.
- Make ahead. Mushroom meatloaf actually benefits from time spent in the fridge as it builds on the flavor profile. Put it together the night before, refrigerate, and bake the next day!
- Veggies - You can PACK in the veggies. Lots of mushrooms, or add some cooked spinach!
- It's stuffed - seriously, the best part. It's time to dial up the awesome on stuffed meatloaf!
🛒 Key Ingredients
Here are the main ingredients that make this meatloaf recipe amazing! Most of the others are spices that are usually already in the pantry or easy to find at the grocery store.
- Mushrooms - baby bella because they're easy to find and available at most grocery stores, easy on a budget, and have a great taste and texture stuffed into meatloaf.
- Onions - yellow, Vidalia, or white onion can be used in this recipe. All are sweeter varieties that caramelize well.
- Ground beef - lean ground beef like 80-95% lean works best for this recipe, so that there's less excess grease after baking.
- Mozzarella Cheese - brings the filling together and is the melty heart and soul of the recipe. Fresh is great, shredded works very well!
- Beef bouillon - this brings a savory depth of flavor needed, and tastes much better than just adding more salt.
- Breadcrumbs - plain breadcrumbs help add stability and soak up excess grease as the meatloaf cooks.
- Baby Bella mushrooms- Go as FANCY as you want. Shiitake, Maitake, Oyster, Portobello, Cremini, all would work well.
- Mozzarella Cheese - Any cheese with good melting power like Havarti, Gouda, Gruyere, a mild Swiss, or even a mild cheddar would work well.
- Ground Beef - can be swapped with ground turkey or a mix of ground pork and beef.
- Butter - can be substituted with a neutral oil like vegetable or canola oil with higher smoking points.
- Breadcrumbs - oat flour or quick oats may change the texture a little but work!
Step 1. In a frying pan over medium heat, melt the butter, add the onions and salt, and cook for about 10 minutes until the onions are soft and translucent and starting to turn golden brown.
Step 2. Add in the mushrooms and cook for another 10 minutes until the mixture is cooked down to about 1.5 to 2 cups or about 270 grams, stirring often to prevent burning.
💡 Pro Tip: You can leave the salt out from the onions if you wish, but it helps draw out the excess moisture to caramelize them more effectively, not to mention adding flavor to both the onions and the mushrooms.
Step 3. When fully caramelized, the onions should have a very soft jammy texture, and both the onions and mushrooms should be a dark golden brown. Set aside and preheat the oven to 350℉.
Step 4. Combine the ground beef, eggs, spices, and bread crumbs with the Worcestershire sauce in a bowl and mix well until combined.
💡 Time-Saving Hack - Buy pre-sliced mushrooms to make prep go quicker. You can also mix together the meatloaf while the onions and mushrooms are cooking to work efficiently.
Step 5. Line a loaf pan with tin foil and spray with baking spray. Use ⅔ of the meat mixture to spread into the bottom of the pan and up the sides to make a "meat boat" with a hollow in the middle to hold the filling.
Step 6. Sprinkle ¾ cup mozzarella cheese in the bottom of the hollow of meatloaf.
Step 7. Pour the cooked mushrooms and onions into the meatloaf over the mozzarella cheese. It's okay if they're still hot.
Step 8. Sprinkle another ¾ cup mozzarella cheese over the mushrooms and onions.
Step 9. Use the last ⅓ of the meat mixture to spread over the top of the cheese, and press down the sides so that it seals in the filling.
Step 10. Sprinkle ½ cup mozzarella cheese on top of the meatloaf and bake for 50-60 minutes until the internal meat temperature reaches 160℉ and the top (cheese) is starting to turn golden brown.
❓Frequently Asked Questions
The binder in this recipe is the eggs, while the breadcrumbs help soak up the excess grease.
Yes, cooking them first significantly improves the flavor and texture, but most of all cooks them down so they fit into the meatloaf.
A sweet variety such as Yellow, White, or Vidalia onion work best for meatloaf. Other types may not be the flavor profile we want or caramelize as well.
Yes! You can make this ahead of time and leave it unbaked, and refrigerate for up to 2 days or freeze for up to 3 months. Remove from the fridge while the oven preheats and bake as directed, or thaw completely if frozen before baking.
Some prefer to make and bake the meatloaf, cool, and freeze it for another time.
Some simple sides are buttered corn, peas, green beans, or mashed potatoes. Some fancier vegetables are roasted asparagus, squash, or sweet potatoes.
- Swap out an onion for a small diced bell pepper.
- Add in a handful of spinach to the mushrooms while they cook.
- Spread a few Tablespoons of tomato sauce on top of the meatloaf before adding the cheese last.
- This is rather excellent with a serving of mushroom or beef gravy.
Refrigerate: After cooling, transfer to an airtight container and refrigerate for up to 3 days.
Freeze: After cooling (or if making ahead, see Frequently Asked Questions), transfer to a freezer-safe container and freeze for up to 3 months.
It is not recommended to re-freeze meat once it has been frozen and thawed for food safety reasons.
✅ Top Tips
- Safety First: Make sure you use meat that is not expired and has been refrigerated or frozen/thawed safely. Be sure to disinfect surfaces after preparing raw meat and cook until the internal meat temperature reaches 160℉
- Pre-sliced mushrooms help to save time when making this recipe.
- Work efficiently by mixing the meatloaf together, lining the loaf pan, and preparing the "meat boat" while the onions and mushrooms are cooking.
📝 Printable Recipe
Mushroom Stuffed Meatloaf
For The Filling
- ¼ cup butter salted
- 2 medium onions sliced thinly
- ½ teaspoon salt
- 8 oz baby bella mushrooms sliced thinly
- 1.5 cups mozzarella cheese
For The Meatloaf
- 2 lbs ground beef
- ½ cup plain breadcrumbs
- 2 large eggs
- 1 Tablespoon Worcestershire sauce
- 1 teaspoon garlic powder
- 1 teaspoon beef bouillon
- ½ teaspoon ground pepper
- ½ teaspoon dried thyme
- ½ cup mozzarella cheese
For the Filling:
- In a skillet over medium heat, melt butter and add sliced onions and salt. Cook until translucent and tender, stirring ocassionaly, about 10 minutes.
- Add sliced mushrooms and cook for another 10 minutes, until the mixture has cooked down to 1.5-2 cups in volume and onions and mushrooms are dark golden brown. Set aside.
- Preheat the oven to 350℉.
For the Meat:
- In a mixing bowl combine ground beef, breadcrumbs, eggs, worcestershire sauce, garlic powder, beef bouillon, pepper, and thyme. Mix well until combined.
- Line a 9x5 bread pan with tinfoil and spray with baking spray. Layer about ⅔ of the meat mixture in the bottom of the pan and spread up the sides to create a meat boat.
- Layer ¾ cup mozzarella cheese in the hollow of the meat, then add the caramelized onion and mushroom filling. Layer another ¾ cup of cheese on top, then cover with the last ⅓ of the meat mixture and spread evenly to cover the filling.
- Sprinkle ½ cup of mozzarella cheese over the top of the meatloaf. Bake for 50-60 minutes, until beef reaches internal temp of 160℉.
- Carefully drain any grease from edges if necessary. Slice and serve while warm. Enjoy!