Step 1: Preheat your oven to 375°F (190°C).
Step 2: Wash the bell peppers and slice the tops off. Remove seeds and membranes, then set aside in a baking dish.
Step 3: In a large skillet over medium heat, brown the ground beef, breaking it apart as it cooks. Drain excess fat.
Step 4: Add diced onion and minced garlic to the skillet. Sauté for 3-5 minutes until onion is translucent. Stir in rice, salt, tomatoes, zucchini, and seasoning, and mix well.
Step 5: Fill each bell pepper with the beef mixture, packing it tightly. Place any leftover filling around the peppers in the baking dish.
Step 6: Drizzle remaining tomato sauce over the stuffed peppers and top with mozzarella cheese.
Step 7: Cover with foil and bake for 30 minutes. Remove foil and bake for an additional 10-15 minutes until cheese is bubbly and golden.
Step 8: Remove from oven, let cool for a few minutes, then serve warm.
