Cook the spinach in a pan of boiling water for 30 seconds until wilted, then drain and rinse under cold running water to cool. Squeeze out the excess water. Put half the wilted spinach in a blender with 150ml hot water and blitz to a smooth green purée.
STEP 2
Dissolve the yeast in 2 tbsp tepid water. Put the flour in a large bowl with the spinach purée, 2 tsp salt and the yeast mixture. Bring together into a dough, adding up to 50ml more water if it’s too dry. Knead for 5 mins, then leave in a covered bowl at room temperature for 1 hr until doubled in size. After an hour, divide the dough into four pieces, then cover again and leave to prove for another hour.
STEP 3
For the pesto, put the remaining 200g spinach, half the basil, the pine nuts, parmesan, oil, lemon juice and garlic in a food processor and blitz until smooth. Season to taste and loosen with up to 3 tbsp water, if needed. Mix the lemon zest with the crème fraîche and some seasoning and 2-3 tbsp water to loosen. Set aside along with the pesto.
STEP 4
Heat the oven to 240C/220C fan/ gas 9 with a large baking sheet inside. Flatten the proved dough balls into rounds on a floured work surface, then roll each one out until about 25cm wide and 5mm thick. Put each pizza base on its own sheet of baking parchment.
STEP 5
Spoon the lemony crème fraîche over the pizza bases and spread almost to the edges, leaving a small border. Drizzle over half the pesto, then top with the broccoli. Dot over the tomatoes and mozzarella, then sprinkle with the chilli flakes.
STEP 6
Cook one pizza at a time by sliding the pizza on its baking parchment onto the hot baking sheet in the oven and baking for 12-15 mins until the crust is golden and crisp. Repeat with the remaining pizzas, then drizzle over the remaining pesto. Scatter over the leaves from the remaining basil, then drizzle with a little extra virgin olive oil and sprinkle with extra chilli flakes, if you like.