Gently simmer diced onions & minced garlic in butter. Add the prawns and cook for approximately 2 minutes and then toss the prawns. Use a fork to turn any prawns that were not flipped in the toss. Cook for an additional minute and then add the white wine. Toss the prawns and reduce the wine for another minute or two depending on the size of the prawns. Garnish with fresh chopped parsely. Serve with rice pilaf.