Heat olive oil in a large skillet over medium heat.
Add diced onion and red bell pepper to the skillet and sauté for 3-4 minutes until softened.
Add minced garlic and cook for 1 minute until fragrant.
Add ground beef to the skillet and cook, breaking it apart with a spatula, until browned and cooked through, about 6-8 minutes.
Drain excess fat from the skillet if necessary.
Add diced zucchinis, diced tomatoes, dried oregano, dried basil, salt, and black pepper to the skillet. Stir to combine.
Cover the skillet and cook for 7-8 minutes, stirring occasionally, until zucchinis are tender.
Sprinkle shredded cheddar cheese evenly over the skillet and cover for 2 minutes until cheese melts.
Remove from heat and serve warm.