Peel the onions and garlic finely dice both. In a wide pan (or wok), heat 2 table spoons of olive oil. Simmer the onions and garlic until glassy, then add the paprika powder. Following, add the canned tomatoes, saffron and chicken stock. Cover with a lid and simmer for about 12 minutes.

Meanwhile, thoroughly wash the mussels with cold water and remove the beards. Remove any open or damaged mussels.

Cut the chicken breasts into bit sized chunks. Rinse the shrimp and dry with a paper towel. Heat another 2 table spoons of olive oil and sautee the shrimp and chicken for about 4 minutes. Season with salt and pepper and set pan aside.

Prehead oven to 225 degrees Celsius. Clean the red bell pepper and cut it into small cubes.
Add the rice to the first pan (containing the onion, tomato mix) and simmer for about 5 minutes.

Add the frozen peas and bell pepper cubes and stir. Season with salt and pepper. Add the mussels, chicken and shrimp on top of the rice.

Drizzle the whole Paella with the remaining olive oil and put it in the preheated oven for about 15 minutes. Take the paella out of the oven, and remove any mussels that didn't open. Serve right away.