In a large paella pan, heat olive oil over medium heat. Season the chicken generously with salt and pepper and brown until golden on both sides. Remove from pan and set aside. Sauté the chorizo briefly and remove from pan.
Briefly brown the scallops for 1-3 minutes and remove from pan. Repeat with shrimp until barely colored, but not cooked thru, and remove from pan with rest of the proteins.
If necessary, add additional olive oil to the pan (at this point you need about 1/4 cup). Add onion, garlic, paprika, and a pinch of saffron. Season with salt and pepper and let cook until onions are translucent, about 3-5 minutes over med-low heat.
Add tomato purée and stir. Add white wine and briefly cook.
Next, stir in rice over med-low heat. Incorporate broth and stir well, adding in sautéed chicken and chorizo, tucking it in at different intervals. Cover the paella pan with foil and let cook for 25 minutes over a low simmer. Do not stir.
Remove foil, tuck in mussels, then replace foil, and cook another 15 minutes.
Remove foil and decoratively place the cooked shrimp and scallops in with the paella and scatter the top with peas. Place foil back on pan and let simmer over low heat for the last 5 minutes of cook time.
Remove foil and loosen up the rice, carefully adjusting with a little extra stock or wine if necessary. Garnish top with roasted red bell pepper strips and lemon wedges. Serve at once.