Wash and dry the tomatoes thoroughly. Cut them in half and place them on the curved side on a baking tray lined with wax paper. Sprinkle each one with a pinch of salt and cane sugar, add on top the peel of lemon, well washed and dried, sprinkle them with a bit of oil and bake them at 200°C for 20 minutes. Sauté the chards in a pan for 10 minutes with the peeled clove of garlic, two tablespoons of oil and a pinch of chilli pepper. Slice the mild Provolone Valpadana P.D.O. into very thin slices. Roll out the mix into two round pizzas with diameter of 28 cm. Place them on two baking trays greased with oil and put them in the oven at 250° C for 10 minutes. Remove from the oven, add the slices of cheese and put back in the oven for another 10 minutes. Take out of the oven and place the baked tomatoes and spinach on the pizzas. Put the baking tray back in the oven a couple of minutes, then take it out and serve.