Are you sure it was squid and not cuttlefish? Most of the dishes round where I am in Spain (east coast) that call for the ink are made with cuttlefish (sepia in Spanish) rather than squid. One of my all time favourite dishes is arroz negro or a risotto nero. Ideally you want not only the ink for this but also the pinkish creamy goo inside the cuttlefish. I don't know what this stuff is and have just had a quick look in Google but am none the wiser. I had assumed it was roe, but that might not be the case. Adding this creamy stuff takes the whole dish to another level.
There are lots of recipes on Google for Risotto Nero, but I make a very, very simple one. First you want a clean cuttlefish. By the look of it, things are very different in the States. Here in Spain, you go to a fishmonger's in a market, point to the one you want and they get on and deal with it for you. For just two of us, I buy a smallish sepia weighing around 1/2 lb. Here it will cost me between €2 and €3.
When I get my sepia home, I've usually got the white flesh of the fish, a tiny little sac of ink that I immediately place in a cup so there's no chance of it going all over the kichen or me, and another, larger sac of creamy goo if my chosen sepia had one.
The dish itself could hardly be easier. Wash and chop the white sepia flesh into bite-sized pieces. Chop an onion and a clove or so of garlic and fry in olive oil or butter, as you prefer. When it's translucent (not brown), add the sepia and fry for a while until you start to think that must be done by now, surely. It pays to fry it for a while to reduce the chewiness. How long depends on the thickness of the flesh. You want to be able to just break it with the end of a wooden spoon. Meanwhile, get your risotto stock going. When your sepia is ready, for your first addition of liquid use something like a white vermouth. I like Noilly Prat. Then start adding the stock and continue to make risotto as normal. About five minutes or so before the end, carefully pierce the ink sac and empty the contents into a smallish cup. Discard the sac itself Take great care not to get any ink on you or your kitchen worktop unless you have something like marble or corian. If you do get any on something you value, clean it off immediately, otherwise you'll be cursing that black blob forever more. Back to the cup - dilute the ink with a ladle or so of stock and then stir that into the risotto. Two minutes or so before the end, pierce your sac of pinkish cream and stir that in too. Discard the sac.
Serve with mounds of freshly grated parmesan and black pepper to taste. On the salt front, I hardly ever add salt to my dishes. Add whatever you like whenever you like.
You get versions of this dish with leeks and all kinds of whatnot in it. Prawns on top and so on. If you were doing this for a special meal, you might want to put other seafood on top to decorate it. But when it's just me and my partner, I prefer it dead plain to make the most of the creaminess and the tang of the sea in the ink. To make the most of the colour, serve on white plates.
Here in my household, we eat this with a certain sense of reverence. Seems daft to say it but there you go. Partly because it really is extremely good and partly because the sepia is a clever creature and I'm never entirely sure I ought to be eating it.