Rinse rice and cook according to package directions, about 15-20 minutes.

Preheat oven to 350F.

While rice cooks, heat olive oil in a large pan on medium-high. Once hot, sauté garlic, onion, bell peppers, and all spices for about 7 minutes. Then, add in baby spinach and cook until wilted, about 2 minutes.

Transfer the cooked veggies to a large casserole dish. Then, using the same pan, cook shrimp 1-2 minutes per side, until pink and opaque. Work in batches, as needed. If using pre-cooked shrimp, you can skip this step!

Place all the cooked veggies, rice, shrimp, and tomato sauce in a large casserole dish. Season with salt and pepper, then toss to combine everything well. Break up the feta cheese and sprinkle on top of the entire dish.

Transfer the casserole dish to the oven and allow to bake for 20 minutes. The cheese should be slightly melted and browned, and the dish will be warmed through.

Garnish with freshly chopped basil and extra pepper, if desired. Serve hot!