- In a large pot, bring the cauliflower, onion, and milk to a boil. Cover and simmer for about 15 minutes. Drain well.
- In a food processor, purée the cauliflower with the butter until smooth. Season with salt and pepper. Keep warm.
- 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.
- In the same skillet, add the remaining butter and chocolate and reduce until the sauce is slightly syrupy, about 1 minute. Adjust the seasoning. Serve with the mashed cauliflower. Serve the shrimp on the mashed cauliflower and top with the white chocolate sauce.