There are many varieties of snapper, but red snapper has distinctive bright red metallic skin that fades into pink near the belly. When you're picking out a whole snapper, look for eyes that are clear and red. The flesh should be firm to the touch.  Snapper has become so ubiquitous that it's often used as a catchall term for any kind of white fish. For this reason it's commonly mislabeled as a similar but less desirable fish, like rock cod. When you buy snapper, be sure to do so from a trusted fishmonger so you'll know you're buying the real thing.  Ask for the fish to be gutted and cleaned, unless you want to do so yourself. You’ll need about ¾ of whole snapper per serving. Be sure it's completely preheated before you put the fish in the oven. Choose a metal, glass or ceramic baking pan or dish that's just large enough to hold the fish. Line the pan with aluminum foil to prevent the fish from sticking. Red snapper is delicious with light seasonings that complement its fresh flavor. Sprinkle salt, pepper and lemon juice to taste inside the fish’s cavity. Add pieces of butter inside the fish to keep it moist while it bakes. Season the outside with more salt and pepper.  If you want the dish to have an herbal taste, add sprigs of thyme, rosemary or basil inside the fish's cavity. For a complete meal, place sliced carrots, onions or potatoes around the fish in the baking dish. The vegetables will cook along with the fish. Place the baking dish in the oven and cook the fish for 45 minutes, or until the fish is cooked through. It can be a little tricky to tell whether the fish is ready, but you know it's done with the flesh is no longer translucent.  After 40 minutes or so, check the fish to see if it's done. You can gently pull back some flesh with a fork. If it looks white and easily flakes off, it's ready. If it's still a little rubbery, it needs more time. Return it to the oven if it needs more time, then check again in five or ten minutes. Whole red snapper looks impressive on a platter surrounded by fresh...

TL;DR in Vietnamese:
Chọn cá. Làm nóng lò nướng trước đến 175 độ C. Chuẩn bị khay nướng cá. Ướp gia vị. Nướng cá. Chuyển cá vào đĩa ăn và dọn lên.