Step 1

Preheat oven to 350 degrees

Step 2

Cut the tops off of the bell peppers and take out the seeds. Place cut side down on a large baking sheet and bake for 10 minutes.

Step 3

Heat the oil over medium heat in a large skillet.

Step 4

Once hot, add the onion and ground beef and cook until browned. Drain off fat if desired.

Step 5

Then, add the mushroom, garlic, and zucchini. Saute until veggies are tender, 5 - 8 minutes.

Step 6

Season with salt and pepper.

Step 7

Stir in 1 Cup of marinara sauce and mix to combine. Taste and add more salt and pepper if needed.

Step 8

Arrange bell peppers in a medium-sized baking dish and spoon the filling into each bell pepper. Spoon additional marinara sauce over each bell pepper to keep them from drying out. Then, lightly sprinkle with dairy-free mozzarella cheese if desired.

Step 9

Bake for 30 minutes at 350 degrees.

Step 10

Serve hot.