Make the farinata batter ahead of time. Whisk chickpea flour, water, salt, rosemary, lemon zest, chilli flakes and a good grind of black pepper together until smooth, then set aside, covered, for a minimum of two hours.
Preheat oven to 250C (485F) fanbake, with a shelf towards the top of the oven (either the top shelf, or next one down) and a shelf in the middle.
Wash broccoli and trim off any tough or knobbly bits from the stalk. Chop florets and stems into even sized pieces. Put them in a bowl, pour over coconut oil and toss gently to coat. Tip out onto a baking tray, season well with salt and pepper, then put in the oven on the middle shelf.
When the broccoli has been cooking for 10 minutes, heat your frypan (skillet) to a very high heat. Add 3 tbsp coconut oil, and when it reaches smoking point, quickly pour in the farinata batter. The oil will swirl around and through the batter, leaving some on the surface.
Carefully transfer the hot pan to a high shelf in the oven, and switch the oven to grill/fan grill (broil). This is a good opportunity to give the broccoli a shake too, it should be colouring up nicely.
Let the farinata cook for 10-12 minutes, or until deeply golden and pulling away from the edges of the pan. It should have no 'jiggle'. Don't be concerned if it puffs up while cooking, it will flatten again when removed from the oven.
Remove farinata and broccoli from the oven. Pile charred broccoli on top, sprinkle with capers and parsley, a good grind of black pepper, and squeeze fresh lemon juice over everything. Slice into wedges and serve immediately, while everything is hot.
Preparation time does not include resting time for the batter.