This is one of the ΓÇ£secret ingredientsΓÇ¥ of the cooking of the Catalonia region of SpainΓÇönot really a sauce, and never served by itself, but a condiment to be stirred directly into stews, soups, and sauces a few minutes before they are finished cooking. Picadas destined to be used with meat, poultry, or game dishes often include a bit of chocolate; those to be used with fish sometimes have fish roe or livers added.
Heat in a small skillet over medium heat:
1 tablespoon extra-virgin olive oil
Add and brown:
1/2-inch thick slice French bread or Italian bread
Crumble and place in a mortar or small food processor or blender. Pound with a pestle or process along with:
1/2 cup whole blanched almonds, skinned hazelnuts, and pine nuts, or all almonds, coarsely chopped and toasted
2 cloves garlic, halved
8 black peppercorns (optional)
Salt to taste
Pinch of toasted saffron threads (optional)
Remove the mixture to a bowl and thoroughly work in with a fork:
3 tablespoons extra-virgin olive oil, or as needed
1 teaspoon finely chopped fresh parsley
Let stand until the picada holds together in a thick paste, about 30 minutes. The picada will keep, covered and refrigerated, for up to 2 days.