Sumac is a dried berry of the sumac bush or small tree that grows in subtropical and temperate regions including the Mediterranean. I couldn’t source them here in Spain for love nor money so I purchased a couple of boxes from the UK. On the back of the packs it read: Produce of Spain.
In a bowl whisk:
2 tablespoons lemon juice
2 tablespoons extra virgin olive oil
1 small garlic clove, peeled and grated
1/4 teaspoon lemon salt
1/2 teaspoon Sumac, ground