Drizzle some olive oil (about 4 TBSP) and cook the shrimp. Once cook, set the shrimp aside.
When the onion mixture is ready, transer the mixture to the paella pan and add the grated tomatoes ("tomato sauce"). Season with a pich of salt and stir for about 3 minutes.
Add the squid, season and stir. The squid should take about 10 minutes to cook. Turn the heat off.
With the heat off, add the rice. Stir and get everything incorporated together. Now, we want all the flavors to combine.
At this point you can it sit up to 5-6 hours.
Heat the fish broth withthe cuttlefish ink. Stir constantly until the ink is mixed well with the liquid. You can also add a pich if saffron (optional).
Turn the heat on medium. Reserve 1/2 cup of the stock and set aside. (This will only be used if you need it for the rice.) Pour the remainder into the paella pan. Consistency of the rice is important. You don’t want to use too much stock, as you will overcook the rice. Too little stock and you will have crunchy rice. Add the shrimp.
Shake the pan every 5-7 minutes. Don’t stir. The black rice will be ready when the rice is cooked and there is no juice left in the pan. It takes about 20 to 25 minutes.
It’s ready to serve. Traditionally you serve the rice with some aioli.