Mince the garlic, slice the chili peppers, chop the green onions, and crush the peanuts.
Heat the olive oil and 1 tablespoon of butter in a large skillet or wok over medium-high heat.
Add the minced garlic and sliced chili peppers, sautéing for 30 seconds until fragrant.
Add the prawns in a single layer and sear for 1 to 2 minutes on each side until they begin to turn pink.
Lower the heat to medium, then stir in the sweet chili sauce and the remaining 2 tablespoons of butter.
Toss the prawns continuously for 1 minute until they are thoroughly coated in the sauce and fully cooked.
Remove from heat immediately.
Garnish generously with crushed peanuts and chopped green onions before serving.