Here's a spinach pie I've been making for years - I serve it with a sauce made with greek yogurt, crushed dried mint, salt and pepper (all to taste):
Mix together and season to your liking (salt, pepper, garlic powder, any favorite seasonings):
2 boxes frozen chopped spinach, thawed and squeezed as dry as you can get it
1 onion, diced and caramelized (size of onion dependent on how much onion you like)
4-6 oz. feta, crumbled - measure with your heart
2 eggs
Bake in well greased pie plate at 375 for about 35 minutes - the edges will get a bit brown and it will feel firm. It's great hot, warm, room temp, reheated, whatever.