Pre-heat the oven to 200Â°c, 400Â°f or gas mark 6.
Prepare the pizza dough according to the packet instructions, giving you 2 x balls of dough. Roll each one out on a lightly floured surface then sit onto lightly floured baking sheets, turning the edges under to create a crust. Leave to rise while you prepare the tomato sauce and toppings.
Heat 2 tbsp olive oil in a saucepan then gently saute the chopped onion and garlic for about 8 minutes. Add the mixed herbs, chopped tomatoes and puree. Bring to a simmer and cook for 10 minutes until thickened. Season with salt and pepper.
Spread a generous amount of the tomato sauce over the pizza bases, leaving a 1 cm crust. Scatter over the mozzarella and top with the broccolini (halved length-ways if they are particularly thick stems), red pepper, mushrooms and onion.
Add a twist of black pepper and drizzle over some olive oil. Place in the oven and cook for about 15-20 minutes until the top is golden and the dough is crisp.