Heat the chicken broth in a small saucepan over low heat and add the saffron threads to bloom while you prepare the other ingredients.
In a small paella pan or wide skillet, heat the olive oil over medium-high heat and add the sliced chorizo, browning for 2 minutes until the fat renders.
Add the diced onion and bell pepper to the pan, sautéing for 3-4 minutes until softened, then stir in the minced garlic and smoked paprika for 30 seconds.
Pour the dry bomba rice into the pan, stirring constantly for 1 minute to toast the grains and coat them in the flavorful oils.
Pour the saffron-infused broth over the rice along with the sea salt and black pepper, then bring to a boil; reduce heat to a simmer and cook undisturbed for 12-15 minutes.
Arrange the shrimp on top of the rice, pressing them down slightly, and cook for another 5 minutes until the shrimp are pink and the liquid is absorbed.
Remove from heat, cover with a clean kitchen towel for 5 minutes to allow the rice to finish steaming, then garnish with fresh parsley and a lemon slice before serving.