Combine oyster sauce, soy sauce, sugar, and stock in a small bowl.
In a medium saute pan, heat the 3 tablespoons of oil and caramelize the garlic until golden brown. Add 1 cup of the oyster mixture and reduce to a glaze.
In a deep fryer or heavy-bottomed pot, heat the peanut oil to 375 degrees F. Add the beans and fry for about 20 seconds. Remove from oil and drain on paper towels. Add beans to sauce and toss until beans are well coated. Transfer to plate. Garnish with Thai basil or scallions.
Double Blanched Garlic:
Prepare an ice bath. Separate the garlic into cloves and remove the ends of each clove. Fill a small saucepan with water. Salt lightly and bring to a boil. Carefully drop the whole cloves into the water and blanch for 30 seconds. Remove with a slotted spoon and immediately plunge into the ice water to stop the cooking process. Repeat the process. Drain the garlic and dry it well. The peels should slip off easily. Cut the garlic into slices and use as needed.