In a large non-stick skillet, soften the onion in 15 ml (1 tablespoon) of butter. Add the garlic and ginger and cook for 1 minute. Deglaze with the cider and bring to boil. Add the shrimp and cook, covered, for about 2 minutes or until the shrimp are cooked. With tongs, remove the shrimp from the skillet and keep warm on a plate.