Prep all the ingredients including the pepper, tomatoes, artichoke hearts and seafood stock. You want the seafood broth hot before adding to the rice so heat it up in a separate pan just before adding.
Heat the oil in the paella pan over medium heat until hot. Add the onion and cook for a minute or two.
Add the pepper slices and continue cooking for 2 to 3 minutes.
Add the diced tomatoes and continue cooking for 3 - 5 minutes.
Add the artichoke hearts, cover the pan and cook for another 3 minutes.
Add the rice and stir all the ingredients to evenly cover the rice with the oil and vegetables.
Add the pinch of saffron and stir once more.
Add the seafood stock, stir and let it cook on medium low to a simmer. If too hot, reduce the heat. If not hot enough, add some more. Cook for approximately 20 minutes.
While the rice is cooking, give it just one or two more stirs and re-position the pan on the stove top occasionally so it doesn't get too hot on any one part of the pan.
The rice is done when it is "dry throughout and has formed a nice brown crust on the bottom" of the pan.
While the rice is cooking, steam the mussels in another pan so they are ready to add to the dish at the end.
When the rice is done cooking and all the mussel shells have popped open, add the shrimp to the pan cover and cook for a few minutes.
Add the squid, cover and cook for no longer than 1 and ½ minutes.
Return the mussels to the pan and serve with aioli.
Add the rest of the seafood to the top of the rice, cover and cook (steam) until the squid and shrimp are just tender, about 1½ minutes.
Aunt Judy had some cuttlefish ink that she said you can purchase at Amazon. You don't need it, but it does give the rice a rich, dark color.