Cut the tomatoes into rounds that are a ¼ inch (.635 cm) thick, then add the tomatoes into a serving dish, in a circular design and layered around each other
Thinly slice the onion, then break the slices apart and spread over the tomatoes
Crack open the can of sardines, gently remove the sardines and transfer over a cutting board, cut each sardine in half lengthwise and then remove any spines, add the sardines over the salad, then crack in some black pepper over the salad, you can also add in some sea salt in you like
Roughly chop the cloves of garlic and add into a mortar, along with the chopped parsley and a pinch of sea salt, using a pestle pound down on the ingredients until your form a paste, then add in 3 tbsp of the olive oil from the canned sardines and 1 tbsp sherry vinegar, mix together until well mixed
Spoon the dressing over the salad, making sure to evenly spread it around, serve at room temperature or chilled, enjoy!