Preheat your oven to 375°F (190°C).
Heat olive oil in a skillet over medium heat. Cook the onion and garlic until softened.
Add ground beef to the skillet and cook until browned. Drain excess fat if needed.
Stir in diced tomatoes, oregano, paprika, salt, and pepper. Let it simmer for 5 minutes.
Layer sliced zucchini in a greased baking dish. Spread half the beef mixture over the zucchini.
Add dollops of sour cream, sprinkle with cheese, then repeat the layers with remaining beef and zucchini.
Finish with a generous layer of cheese on top.
Bake uncovered for 25–30 minutes, until the top is golden and bubbly.
Let it cool for 5 minutes before serving.