Preheat oven to 375 degrees Fahrenheit.
Place an enameled cast iron braiser on the stovetop at medium-high heat. Sauté chorizo in olive oil to render the fat from the sausage.
Add the diced onion with ½ teaspoon of salt and stir. If there isn’t enough oil to make the onions glisten, add another splash. Sauté until the onions are softened and translucent.
Stir in the garlic, then make a well and add tomato paste to the center of the well. After a minute or two, stir together the aromatic mixture.
Add the rice and coat it well with the aromatic mixture. Stir in the saffron, paprika and 1/2 teaspoon of salt.
Add the dry white wine and use a wooden spatula to deglaze any fond that developed during the previous steps.
Add the broth and stir. Also add any cook-in ingredients (see notes). Turn the heat up to high, and bring to a boil.
Cover the pot and place in the oven. Cook for 50 minutes adding tuck-in ingredients (see notes) at appropriate times.
Remove from the oven. Optionally develop a socarrat (see notes) by placing the uncovered braising pan over medium-high heat for 5 minutes. Either add any top-on ingredients (see notes) to the top of the paella and serve from the pan, or plate portions and add any top-on ingredients directly to the plate.