Wash the spinach and parboil it for 3 min. in boiling water. Take it out, drain, remove the stems and cut it finely. Chop the peppers finely and braise them with 2 tbsp olive oil for 2-3 min. and shortly before removing them from the stove, add the spinach and chopped garlic.
Beat the eggs and add the vegetables, spices and 1 tbsp olive oil to them. Stir carefully and pour this into a pan with a nonstick bottom, in which you've put the rest of the oil to heat up beforehand.
Shake the pan like you would when making pancakes, so that the mixture spreads out all over and then cover with a lid. After about a minute, remove the lid and carefully lift the edges of the frittata from one end so it doesn't stick and if there's a lot of liquid on top - let it spill to the sides so that you can fry easier.
Cover with a lid again and continue in this manner until fully cooked - it takes about 2-3 min. on a medium stove but it's always good to check to make sure it doesn't burn underneath.