- In a 1-quart heavy saucepan cook shallot in unsalted butter, covered, over moderately low heat, stirring occasionally, until softened.
- Add cream and simmer, uncovered, until reduced to about 2/3 cup.
- Remove pan from heat and stir in truffle butter or oil until incorporated.
- Season sauce with salt and pepper and sprinkle with chives.
- Cut Camembert into 4 pieces and arrange on 4 plates.
- Divide warm sauce among plates, spooning it on either side of cheese.
- Arrange pear slices, grapes, and walnuts around cheese and serve bread on the side.