Heat olive oil and butter in a large skillet over medium-high heat.
Add garlic and sauté until fragrant but not browned.
Add prawns, salt, and pepper. Cook until prawns turn pink, about 1-2 minutes each side.
Pour in chicken stock and oyster sauce. Stir and let simmer for another 2 minutes until the sauce thickens slightly.
Remove from heat and garnish with chopped parsley or cilantro.
Serve immediately with lemon wedges.