Bring a pan of water to the boil and blanch the almonds for a few minutes. Drain and set aside to cool, then pinch off the skins.
Toast the almonds in a dry frying pan over medium–high heat. Keep them moving to prevent burning; they should be a light golden colour.
In a food processor, pulse the almonds until they resemble breadcrumbs. Add the basil and garlic and pulse a couple of times. Tip into a bowl.
Mix in the tomatoes, pecorino and oil. Season with the salt and pepper.
Bring a pan of salted water to the boil and cook the pasta until al dente. Drain it and stir the pesto through. Serve, garnished with basil, with plenty of pecorino.