Preheat oven to 400 degrees F and line a baking sheet with aluminum foil.

While oven is preheating, slice the peppers horizontally – leaving about 1 to 2 inches of space near the stem and the pointed end of the pepper. Carefully dig out seeds and ribs of the peppers.

Drizzle the inside of each pepper with a bit of olive oil. Bake peppers in preheated oven for 8 minutes. Remove from oven and set aside.

To make the filling, heat about 3 tablespoons olive oil in a large skillet over medium-high heat. Add minced onion and cook for about 5 minutes, until soft. Add in minced garlic and cook for another minute.

Add cauliflower rice to the skillet. If cauliflower rice is frozen, defrost it for about 1 minute in the microwave. Stir in rice and add dried oregano, dried parsley, dried basil, salt and pepper to the skillet.

Cook for about 3 to 5 minutes, until cauliflower rice just begins to crisp. Stir in diced tomato and chopped spinach, reducing heat to medium. Cook filling for 7 to 10 minutes, until flavors are combined.

Taste and adjust salt and pepper, as needed. Remove from heat and stir in ½ cup shredded mozzarella cheese.

Spoon filling into the peppers and return baking sheet to the oven for 20 minutes. Remove, garnish with fresh parsley, as desired, and serve.