First, prepare the base. Add the flour and dried mixed herbs to a large bowl, season, then whisk in 250ml cold water. Cover with a clean tea towel and allow to rest for at least an hour.
Meanwhile, toss the courgette, onion and broccoli with the oregano and 1 tbsp olive oil and season. Heat a griddle plan until smoking, and char the vegetables. The courgette ribbons and onion will only take 1-2 minutes on each side, but the broccoli may need a little longer. Set aside on a plate.
Heat the remaining olive oil in a saucepan and cook the garlic over a low heat for 2 minutes until fragrant. Season, add the tomato puree and chopped tomatoes, then turn up the heat and simmer for 5 minutes, until reduced slightly.
Preheat the oven to 180°C/gas mark 4. To cook the base, lightly brush a 26cm ovenproof frying pan with the olive oil. Pour in the batter and swirl around the pan to coat – it should be about ½cm thick. Cook on the hob over a medium heat for 2-3 minutes until it lifts easily, and carefully flip – you may need a plate to do this. Cook for another 2-3 minutes until golden brown.
Dollop the tomato sauce over the pizza base and spread it out with the back of a spoon. Add the griddled vegetables and bake in the oven for 8-10 minutes. Serve with the leafy green salad.