8 ounces (5 to 6 medium) tomatillos, husked and rinsed
Fresh hot green chiles, to taste (roughly 2 serranos or 1 jalapeno), stemmed
5 or 6 sprigs fresh cilantro (thick stems removed), roughly chopped
Scant 1/4 cup finely chopped onion
Peel the garlic and pick the herb leaves, then finely chop on a large board with the capers, gherkins and anchovies.
Place in a bowl, add the mustard and vinegar, then slowly stir in the oil until you achieve the right consistency.
Balance the flavours with black pepper, a bit of sea salt and maybe a little more vinegar.