Preheat the oven to 190ºC/375°F/gas 5. Scrub the potatoes, then parboil in a large pan of boiling salted water for 10 minutes, then drain. Toss the chicken with 1 tablespoon of olive oil and a pinch of sea salt and black pepper, then place skin-side down in a large wide casserole pan on a medium-high heat. Cook for around 10 minutes, or until the skin is beautifully golden, then turn over. Pick most of the herbs into a pestle and mortar, add a pinch of salt and bash to a paste. Muddle in 3 tablespoons of olive oil and the juice of half a lemon, then put to one side. Slice up the chorizo, then sprinkle into the pan with the drained new potatoes and toss everything together over the heat. Add the tomatoes – leave any cherries whole, and halve or quarter any larger tomatoes. Pour in half the herby sauce and toss together again, then pick over the remaining herb leaves. Arrange everything in a single layer, making sure the chicken is skin-side up, then roast for 40 minutes, or until the chicken is falling off the bone. Drizzle over the remaining herby sauce, then serve up, spooning over the tasty juices from the bottom of the tray. Delicious with a crunchy seasonal salad and some crusty bread for mopping up.