Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
Add the 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, then remove the cooked beef to a bowl and set aside.
In the same skillet, add the remaining 1 tablespoon of olive oil.
Add the chopped onion and cook until softened and translucent, about 3-4 minutes.
Add the minced garlic and cook for 30 seconds until fragrant.
Add the diced zucchini to the skillet and sauté until tender, about 5 minutes.
Return the cooked ground beef to the skillet with the vegetables.
Stir in the dried oregano, salt, black pepper, and crushed red pepper flakes.
Cook everything together for 2-3 minutes to combine the flavors.
Sprinkle the shredded cheddar cheese evenly over the top, cover the skillet, and cook for 1-2 minutes until the cheese melts.
Remove from heat and serve warm.