Slowly steam the onions in a little olive oil. Add the chilli peppers and bell peppers. When the onions are steamed blond. Add the tomatoes, garlic, herbs and some pimento d`Espelette, season with salt, pepper and lightly add sugar. Steam for about 30 minutes.
Beat the eggs with the baking flour and add to the piperade. Let set for 5 minutes while stirring. Spread on plates and serve with the ham slice.