Preheat the oven to 180 ° C. Rinse beans and drain. Crumble feta.
Peel garlic and chop finely. Peel the onion and dice, cut the spring onions into fine rings. Whisk the eggs with milk, salt and pepper.
Heat the oil in an oven-proof pan, sauté the red onion and garlic briefly. Add the onions and fry them alos briefly. Mix in the beans (except 3 tbsp.). Spread eggs and feta on top and fry for 2 minutes.
Then let stand for about 15 minutes in the middle of the oven.
Meanwhile halve or quarter the tomatoes. Mix with lemon juice, olive oil, remaining beans and spinach. Season with salt and pepper.
Arrange fittata and put the salad on top.