Preheat your oven to 350°F (175°C) and grease a medium-sized baking dish with olive oil.

In a skillet, heat 1 tablespoon of olive oil over medium heat. Add 1 chopped onion and 2 minced garlic cloves, sauté for 3-5 minutes until onion is translucent.

Add 1 pound of lean ground beef to the skillet, cooking until browned for 5-7 minutes. Drain any excess fat if needed.

Stir in 1 can of crushed tomatoes, 1 tablespoon of Italian seasoning, salt, and pepper to taste. Let simmer for 2-3 minutes.

Slice or shred 2 medium zucchinis and lightly salt them, letting them sit for 10 minutes to draw out moisture.

Layer your casserole: start with zucchini, then beef mixture, and top with 1 cup of cheddar cheese and ½ cup of parmesan cheese.

In a bowl, whisk 2 large eggs. Pour this evenly over the layered casserole.

Bake in the oven for 30 minutes until cheese is bubbly and golden, and egg is set.

Let the casserole cool for 5-10 minutes before slicing and serving.