Serves 4
3 tablespoon vegetable oil
1 tablespoon mushroom soy sauce (dark soy sauce)
1-1/4 lb. boneless sirloin, cut into strips 2 inches long, 1-1/2 inches wide and 1/4 inch thick
2 garlic cloves, smashed
1 small pineapple (about 1 lb.), peeled, cored, sliced 1/4 inch thick and julienned, or 12 ounces canned pineapple slices, julienned
2 tablespoon fish sauce (or to taste)
2 teaspoon soft brown sugar
1 tablespoon cornstarch, dissolved in 1 teaspoon water (optional)
2 spring onion (scallions), cut into 1-1/2 inch pieces
Combine 1 tablespoon oil and the soy sauce in a shallow bowl and marinate the beef in this mixture for 10 minutes.
Heat the remaining 2 tablespoon oil in a large skillet or wok over medium high heat and saute the garlic until golden brown, 50 to 10 sec. Add the beef, stirring well (to separate the pieces), then add the pineapple, fish sauce and sugar and stir-fry for few minutes.
If you want a thicker sauce, add the cornstarch-and-water paste to the pan, stirring well, and cook until the sauce has thickened, about 1 minute. Stir in the scallions and serve immediately with rice.