To make the salsa, quarter the cherry and baby plum tomatoes. Deseed the larger plum tomatoes, then cut into strips. Pick and slice the basil leaves, then peel and finely slice the garlic.
Place into a bowl with the oil and lemon juice, toss well, then season to taste with sea salt and black pepper.
Place the steaks on a board and season with salt and pepper. Lay 4 sage leaves on each steak, then cover each with 3 slices of prosciutto.
Take a meat hammer and pummel the steaks so that the prosciutto sticks to them, then lightly oil.
Get a griddle pan really hot, then add the steaks and cook to your liking, turning frequently.
Allow the steaks to rest for 5 minutes, then serve with the salsa picante, the chopped herb leaves and dressed with a little olive oil, lemon juice, salt and pepper.