Heat a large paella pan (or flat skillet) over medium-high heat. Add the chorizo and cook until slightly brown (approximately 2-3 minutes). Remove the chorizo from the pan and set aside.
There should be some fat left in the pan from the sausage. If not, add 1-2 tablespoons of olive oil. Add onion to the pan and cook until softened (about 5 minutes).
Add the garlic, paprika and saffron and cook about 1 minute.
Add the tomatoes and cook about 3 minutes, until the color has darkened slightly. Scrape any browned bits from the bottom of the pan. Stir the rice and salt into the tomato mixture.
Add the wine and warmed chicken stock. Stir to combine. Arrange rice mixture in an even layer in the skillet. Sprinkle the chorizo slices on top, reduce heat to medium-low and cover the pan.
It is important to avoid stirring or disturbing the rice until most of the liquid is absorbed and you can hear the rice "crackling" (about 10-12 minutes).
Add the roasted red peppers, shrimp, seafood blend (or fresh seafood) to the pan, tucking them into the rice.
Cook on a low simmer until heated through (if using fresh seafood, simmer until clams and mussels are open); about 8-10 minutes.
The rice should be browning and a little crispy (not burnt) on the bottom.
Sprinkle with parsley and serve with lemon wedges.