Trim the spring onions, then dry-fry in a pan set over a high heat for 2–3 minutes, until charred, then remove and set aside.
Peel and finely chop the garlic and onion, then finely chop the spring onions, pepper, tomato and parsley stalks (reserving the leaves for later). In the same pan, heat a tablespoon of oil over a medium heat. Add the chopped veg and leave to cook for a few minutes. Halve the padron peppers, then add to the pan and cook everything for 7 minutes, until all the veg have softened.
Blanch the green beans in a small pan of boiling water for 3 minutes. Drain in a colander and leave to steam-dry.
Peel the prawns and add to the pan for 1 to 2 minutes, until they just start to turn pink. Stir in the rice and turn up the heat.
Soak the saffron in a little hot water, then add to the pan after a couple of minutes, along with the wine or stock. Cook until the liquid has evaporated and the rice sticks to the pan slightly, going a bit crispy on the bottom; this will take 10–15 minutes.
Tear in the olives, add the lemon zest and a little juice, and season. Stir in the spring onions, green beans and parsley leaves. Serve with a lemon wedge.