Stocks are just about the easiest thing you can make in an instant pot that provides great flavor and doesn't take much time. You can use any seafood shells for your stock or mix them together for a more broad seafood flavor. In this recipe, I use shrimp shells. You don't need a ton either, I used about 10-15 shrimp shells and that was plenty to get a good base flavor.
I like to save my shrimp shells when I'm making fried shrimp or another shrimp dish so that I have enough to make stock. You can simply freeze the crab, shrimp, fish heads/tails, or lobster shells in a ziplock freezer bag until you are ready to use them in a stock. If you already have enough to use now, you can go ahead and make the stock and freeze the stock in a ziplock bag or in ice cubes so you can use them individually for sauces or to flavor up some rice or in your paella.
Since you are going to strain your final product, there is no need to be precise with your preparation, just roughly chop the ingredients. Some people say to throw in the skins and dont bother peeling, but I don't like doing that because it seems unsanitary to me.
2 stalks of celery
1 large carrot
1 large onion
2-3 cloves of garlic
1 Tbsp oil
4 cups water
seafood shells/fish pieces
Lets get cooking
1. Set your instant pot to saute, and roughly chop the celery, carrot, garlic and onion. Add the oil and then drop in the seafood shells and chopped vegetables into the pot and stir until it is sweated out and the onions are turning translucent.
2. Add the water into the pot, close the lid, and then set the instant pot to the pressure cook setting for 10 minutes on high pressure.
3. Once the 10 minutes is up, release the steam and open when safe. Take a strainer and place it over a bowl or measuring cup like below to strain the vegetables out, leaving a smooth, clean stock!
4. You can either use this to now directly add some seafood and some veggies to make a seafood soup/stew, or save it by letting it cool and putting it in a ziplock bag or ice cubes to use whenever you need it!