1. Peel the shrimp and set the shells aside. Season shrimp with salt and pimentón. Set aside.

2. Pour the stock in a medium saucepan and bring to a low simmer.

3. Add enough olive oil to just cover the bottom of the paella pan or skillet and heat over medium heat. Add the shrimp shells and shrimp and sauté until it has achieved some color and is about half-cooked. Add bell pepper and stir until the color just starts to change, around 1-2 minutes. Remove from the pan and set aside.

4. Add additional olive oil to the pan and sauté the grated onion, garlic, and tomatoes over medium-low heat until the onions have turned translucent and the tomatoes have darkened in color, about 7-10 minutes. This is your ​sofrito​.

5. Add the rice and mix it into the ​sofrito,​ once it turns translucent on the edges add just enough of the simmering broth to cover the rice. Even out the rice with a wooden spoon and then set it aside. It’s very important not to stir the rice after this point.

6. Reduce the heat to low and continue to cook until the liquid is almost absorbed. Return the shrimp and vegetables to the pan and add the cleaned mussels and clams, arranging them carefully, and add additional broth. Keep rotating the pan as the rice cooks and repeat this process until the rice is fully cooked and the mussels and clams have opened up. Toss any that do not fully open as they were already dead when the cooking process begin and are not fit for consumption.

7. If you are having trouble with the rice cooking unevenly or if the paella pan is too big for the burner, you can place the entire pan in the oven at 375 degrees and finish cooking it there. Add the seafood, vegetables, and additional broth to the pan, cover with aluminum foil, rotating the pan every 5-7 minutes when new additional broth is added.