Remove the prawns from the freezer. Let them sit briefly until they separate, then cook them right away without thawing.

Sauté the minced shallot and garlic in a pan until fragrant. Add the prawns and stir-fry until they turn color and firm up. Add 1 tablespoon fish sauce, a pinch of MSG (optional), 1/2 tablespoon sugar, a little chili sauce, 1/2 teaspoon black pepper, and a splash of water. Stir until the sauce is almost fully reduced, then turn off the heat.

Serve with hot rice.