This condiment, richly flavored with fine herbs and anchovies, is the perfect accompaniment to grilled fish as well as cold or grilled meats.
Cook the egg in a saucepan for 10 minutes, then cool it, peel it and chop it finely. In addition, pat the anchovy fillets dry on absorbent paper. Immerse the watercress and spinach for a few minutes in a pan of salted water, drain and squeeze as completely as possible.
Mix these blanched herbs and the finely chopped herbs in a bowl. Add the peeled and crushed garlic cloves, salt moderately and pepper, then mix quickly. Add the softened butter in small portions and mix again. Finally add the anchovies cut into small pieces. Blend again.
Incorporate the chopped hard-boiled egg last, then assemble this sauce by pouring the olive oil in a trickle and whisking vigorously until a fairly firm and homogeneous consistency is obtained. Taste and adjust the seasoning.
You can also add to the ingredients of this sauce well-drained and coarsely chopped capers, and 1 or 2 also chopped gherkins. It is above all the mixture of fresh herbs that makes it so attractive.
Source:Regional Cuisines of France. Editions du Fanal.
