sweet Italian sausage • plus 1 tsp extra-virgin olive oil • store-bought pizza dough • tomato paste • garlic cloves, finely chopped • coarse salt • fresh mozzaella, thinly sliced • red pepper flakes • whole peeled canned tomatoes, crushed • garnish: flat-leaf parsley leaves and Arugula, tossed with olive oil and vinegar, plus parmesan shavings