In a big wok or frying pan, heat 1 Tablespoon of vegetable oil over medium heat. Add the crushed garlic and cook just long enough to start frying a little.
Add the clams and stir into the garlic. Cook them, turning over often, until the shells start to pop open, or about 2 - 3 minutes.
Add nam prik pao, soy sauce, oyster sauce, and sugar. Stir in well and let the sugar melt and blend into a nice sticky coating on the clams.
Add a small amount of water. Stir well to loosen up the seasonings and make a nice sauce. When the sauce is smooth and bubbling, add sweet red chili.
Turn off the heat and add Horapah basil. Toss in well and serve.