Samfaina or xamfaina, as it is known in the regions of Girona, is one of the basic sauces of Catalan cuisine, together with allioli (garlic mayonnaise), romesco sauce, the minced meats, sofritos (basic tomato sauce), the marinière sauces, etc. It is very similar to the Spanish pisto and the French ratatouille. The ingredients change and have many interpretations and variations, with a varying amount of peppers, with or without courgettes, thicker or thinner sauce, without onion, roasting the aubergine previously instead of frying it in oil, etc. It is very important however to use the freshest products. An aubergine which is too old can make the xamfaina bitter, particularly if you add the skin. Some people add a pinch of black or white pepper to make it a little spicy, while others add a spoonful of sugar if the tomatoes are acid. If courgettes are used, they should be tender and seedless. Use it as an accompaniment or as a base for casseroles, both meat and fish. It goes very well with cod and with chicken, particularly free-range, or with lamb sweetbreads prepared simply with a xamfaina of pepper and tomato.
Peel the onion and slice finely.
Heat some olive oil in a casserole and add the onion. Fry gently.
Clean the peppers, remove seeds and cut into strips, one finger wide. Add the onion and fry gently.
Meanwhile, peel the garlic, cut into slivers and add to the pan when the pepper and onion mixture is almost cooked.
Scald the tomatoes in boiling water, peel and dice them, and add to the pan. Cook until the mixture is well concentrated. If necessary add a couple of tablespoons of hot water little by little to ensure the roux does not stick to the pan.
Dice the courgettes and add the casserole. Stir gently.
Wash the aubergines and peel, leaving a few pieces of skin, and cut into large dice. Fry gently in a frying pan in one finger of oil, drain well and add to the casserole just before the end of the cooking time.
Season, check that the tomato mixture has reduced to the required thickness and remove from the heat.