Bring chicken broth and saffron to a boil in a small saucepan then turn heat to low and place a lid on top to keep hot.
Meanwhile, heat extra virgin olive oil in a large skillet over medium-high heat then add chicken, chorizo, and shallots, season with salt and pepper, and then saute until chorizo and chicken are cooked through, 5 minutes, breaking chorizo up as it cooks. Add garlic then saute for 1 minute. Add tomatoes and their juices, paprika, and cayenne pepper if using then saute until tomatoes are softened, 3 minutes.
Add rice and hot broth to skillet then stir to combine and bring to a boil. Place a lid on top then lower heat and simmer until rice has nearly absorbed all the broth and is just slightly al dente, 13-15 minutes. Stir in shrimp and peas then place lid back on top and let skillet sit off the heat for 5 minutes. Season with more salt and pepper to taste then serve.