It is called squid. You can just put it in a boiling water with salt for 1 minutes and make a salad with chilli lime and coriander, onion and land tomatoes. Another one way is just clean the squid thoroughly and slice it thinly and dip it in a sauce made out of fish sauce and very spicy chilli. Another one way is just cut it to your finger size and roll it in a flour and deep fry it for 1 and 1/2 minutes and eat it when it is crispy. Another one way is just pan fry it with chilli, garlic, oyster sauce and salt and vegetable