Chop the garlic finely, place the anchovies (if using) and capers on top before finely chopping together. Separately, chop the herbs roughly, then mix them into the caper mixture. Finely chop everything together.
Place everything into a good-sized mixing bowl. Stir in the vinegar, lemon zest, and juice. Season with a little salt and pepper, then slowly stir in the oil in a steady, even flow. The salsa verde will keep well for several days in a jar in a refrigerator.