Heat furnace to 200C / gas 7 at 220C / fan. In a large non-stick baking tray, place the pepper, courgette and red onion and drizzle with 1 tsp of olive oil. Season well and combine to toss. For 20 minutes, roast in the oven until soft and start to brown. Set aside.
Heat to medium the grill. Well, season the flour and mix in a large bowl to form a soft dough with the remaining oil and 4-5 tbsp water. Knead briefly, then roll out to a rough 20 cm circle on a floured surface. Transfer the dough to a large oven-proof, non-stick frying pan and fry for 5 minutes over medium heat until browning begins on the underside.
Turn over and cook another 5 minutes. Spread the tomato sauce over the base, sprinkle with the roasted veg and sprinkle with the cheddar. Grill the pizza until the cheese has melted for 3-4 minutes. Serve immediately with a large green salad, sliced into wedges.