One thing to remember when cooking squid is after you cook it, the squid reduces in size. When i buy squid, i get medium sized ones so when it shrinks it won't be too small. To do this dish, clean the squid thoroughly but not to the point of removing the ink. Remove the cuttlebone, the clear plastic like membrane. Sautee grated ginger (half a thumb), minced garlic (about 5 cloves), an onion and chopped tomatoes. Add the squid and add about 1/3 to half a cup of water depending on the amount of squid. Once the squid starts to cook, the liquids and ink will start to come out, so you don't want too much water. You can easily add water if it's too dry. Add about 1/4 cup of white vinegar and let it boil at low heat. Do not do this at high heat as the squid will toughen, and it would be like eating rubber. Season with salt and cracked black pepper. I like it a bit sweet so i add sugar. If you want this spicy, you can add long green chili peppers (siling haba). This should be done in about 15 minutes. Just like any dish, taste it and if it's good for you, it's good to go! :)
This really goes well with plain white rice.