Preheat the oven to 200ºC/400ºF/gas 6. Drizzle 1 tablespoon of olive oil into a 28cm ovenproof non-stick frying pan on a medium-high heat. Scrub 600g of potatoes and chop into 1cm dice, adding to the pan as you go. Trim, finely slice and add 1 bunch of spring onions. Trim the tough end off 1 head of broccoli (375g), finely chop the remaining stalk and add to the pan. Deseed, finely slice and add 1 red pepper. Season with a pinch of sea salt and black pepper, add 1 teaspoon of smoked paprika, then cook for 15 minutes, or until golden, stirring occasionally. Slice the head of broccoli apart into bite-sized florets, adding to the pan for the last 5 minutes. Crack 8 large eggs into a bowl and beat together, grate in 30g of Cheddar cheese and season with salt and pepper. Mix together well. Roughly chop half the watercress, spinach & rocket (40g) and stir into the pan, then pour over the egg mixture, swirling to coat the base of the pan. Grate over the remaining 10g of Cheddar and cook for 2 minutes, then bake for 10 minutes, or until golden and set. Slide the frittata out onto a serving board and cut into wedges. Dress the remaining watercress, spinach & rocket (40g) in 1 tablespoon of extra virgin olive oil and serve alongside.