Frittata with brown rice and zucchini

Name: Frittata with brown rice and zucchini
Ingredients: 1 cup brown rice (uncooked); 7 eggs; 2 white onions (thinly sliced); 1 green chili (seeds removed and finely chopped (optional- use only if you like your frittata hot and spicy)); 1 zucchini (grated); 1 carrot (grated); a handful black olives (thinly sliced); 1/2 cup parsley (chopped, loosely packed); 1/2 cup feta cheese (crumbled); 1 tablespoon lemon juice; 1 tablespoon lemon zest; 1 tablespoon butter (plus additional to grease the casserole); salt and pepper to taste