For the tomato sauce, put the tomatoes, garlic and olive oil into a saucepan and cook over a medium heat for about 30 minutes, until the tomatoes become pulpy.
Tear up the basil leaves, add to the sauce and season to taste with salt and freshly ground black pepper. Cover with a lid and set aside.
Mix the tepid water, yeast, sugar and olive oil together in a jug. Sift the flour and salt together in a large bowl. Make a well in the centre and pour in the yeast mixture. Mix and knead the mixture together to form pliable dough.
Divide the dough into 10 pieces, each about the size of a tennis ball. Cover with a damp cloth and leave in a warm place for about 20 minutes to rise.
When well risen, dust a clean work surface with a little flour and roll the balls out into flat discs with a rolling pin.
Heat a barbecue grill until hot, then cook the dough discs until lightly toasted on both sides. Remove from the heat and spread a little warm tomato sauce on top. To serve, scatter over your favourite toppings while the pizza is still hot.