These measurements is for a 12 inch paella pan. This paella pan will serve 4 people and 2 cups of rice is the most you can use for this size.
Boil water in a pan over medium heat. Add shrimp or prawns, mussels and clams.
Remove shrimps when color turns pink. Set aside.
Remove clams and mussels when shells open up. Set aside.
Transfer liquid from pan to another container. Save it, to be used later.
Heat olive oil in pan over medium heat.
Add squid and cook for 2 minutes. Set aside.
Fry shrimps for 2 minutes on each side. Set aside.
Add olive oil if needed.
Saute onion and cook for 2 minutes.
Add garlic and cook for 2 minutes.
Add tomatoes and cook until soft.
Saute green beans for 2 to 3 minutes.
Add red bell pepper and cook to 2 minutes. Remove green beans and red bell peppers from pan. Set aside.
Add Spanish smoked paprika. Mix well.
Add arborio rice and mix.
Pour broth from seafood. Make sure you pour 3 ½ to 4 cups broth.
Add saffron and salt. Mix well. This is the last time you will be mixing the rice mixture. Cover pan.
Once liquid boils, lower heat to medium low.
Let it simmer over low heat for 30 to 50 minutes or until rice is cook. If your pan is bigger than the burner, rotate pan so rice cooks evenly.
During the last 15 minutes of cooking and liquid is reduced, put back all the seafood, green beans and red bell peppers. Decorate the pan however you want it by pushing down the seafood slightly on the rice. Turn the heat to medium-high for 3 to 5 minutes if you want "socarrat" or "tutong" to form but make sure you don't burn it. Cover.
Turn off heat and remove pan from burner. Cover Seafood Paella for 5 to 10 minutes.
Serve hot with slices of lemon.
Enjoy!
Notes
I used a 12 inch paella pan which is a good size for my burner. For this recipe, 1 ½ cups of Italian Superfino Arborio rice was enough to feed 4 people. If making more than 2 cups of rice, you need a bigger pan.
If you have no desire decorating your paella, you can skip boiling the seafood. Instead, when the broth boils you may add all the seafood stirring it once. Fifteen minutes before done cooking, add the green beans and red bell peppers.
The paella pan is not non-stick so lower the heat once the rice boils.
After adding the rice, mix it once and don't stir again if you want "socarrat" or "tutong" to form. Fifteen minutes before the dish is done, I turn the heat between medium to high for 3 to 5 minutes to get the crust to form at the bottom of the pan.
If you can get smoked paprika, it is best to use to get that authentic Spanish Paella taste.
You might ask if there is any substitute for saffron - not that I know of.