Heat a large pan or wok over high heat. Add some vegetable oil and swirl to coat the pan.
Add the minced garlic and ginger and stir-fry for about 30 seconds until fragrant.
Add the prawns to the pan and stir-fry until they turn pink and opaque, about 2-3 minutes.
Add the snow peas to the pan and continue to stir-fry for another 2-3 minutes until they are crisp-tender.
In a small bowl, mix together the soy sauce, oyster sauce, and sesame oil. Pour this sauce over the prawns and snow peas and toss everything together until well coated.
Season with salt and pepper to taste.
Garnish with sliced green onions before serving.
Serve the stir-fried snow peas with prawns hot over steamed rice.