Preheat your oven to 350°F (175°C).

In a medium saucepan, bring 2 cups of water to a vigorous boil. Once boiling, add 1 cup of uncooked rice, cover, and reduce to low heat. Let it simmer for about 15-18 minutes until tender.

In a large skillet, heat 1 tablespoon of olive oil and 2 tablespoons of butter over medium heat. Sauté 1 chopped onion for about 5 minutes until translucent.

Add 3 cloves of minced garlic to the onion and stir for another minute until fragrant.

Stir in 3 cups of grated zucchini, 1 teaspoon of salt, ½ teaspoon of black pepper, 1 teaspoon of dried thyme, and 1 teaspoon of dried oregano. Cook for about 10 minutes.

In a mixing bowl, combine the cooked rice and zucchini mixture with 1 cup of shredded cheddar cheese and ½ cup of grated Parmesan cheese. Mix well.

Pour in ½ cup of chicken broth or vegetable broth and mix until evenly coated.

Grease a 9x13-inch casserole dish and spread the rice and zucchini mixture evenly. Optionally, sprinkle additional cheese on top.

Bake in the preheated oven for 25-30 minutes until the top is golden and bubbly.

Let the casserole rest for a few minutes before slicing into squares.

Serve warm, garnished with 3 tablespoons of chopped fresh parsley.