How to make it
Heat 2 Tbsp. olive oil in paella pan on medium-heat grill. Add chicken and cook about 5 minutes, turning to brown on all sides. Add chorizo and brown, another few minutes.
Add 3 Tbsp. olive oil. Add onion, scallions, bell pepper, and garlic. Season with salt and pepper. Cook until vegetables soften, about 5 minutes.
Deglaze pan with sherry, scraping pan to loosen any burned bits.
Add rice, red pepper flakes, and tomatoes. Mix well and cook for 2 minutes.
Add stock, saffron, and paprika. Mix well and cook for 15 minutes, but do not stir again until serving. (Seriously, even if you hear crackling noises from pan bottom. You want that noise.)
Tuck clams and mussels, hinges down, into the cooking rice. Add shrimp. Continue cooking about another 15 minutes, rotating pan every few minutes. If heat doesn’t seem to be distributing evenly, you can close grill or cover pan with foil.
Once rice is tender and shellfish open, remove pan from grill. Drizzle with olive oil and sprinkle with chopped parsley.
Serve with lemon wedges, and make sure to dig up some of the prized socarrat—the caramelized crust on the bottom—for each serving.