Place the almonds in a small, dry frying pan and toast for 5 minutes, shaking the pan frequently, until golden brown. Leave to cool, then roughly chop.
Toss together the tomatoes and 1 teaspoon of the oil, then season. Heat a griddle pan until smoking hot, then add the tomatoes and cook for 3–5 minutes until just charred. Remove from the pan and roughly chop, then toss together with the almonds, garlic, chilli flakes, vinegar and 3 tablespoons of the oil. Season and set aside.
Wipe out the griddle pan, if necessary, then toss the leeks in the remaining oil. Cook in the pan for 7 minutes or until softened and charred. Serve drizzled with the tomato sauce.