Melt the butter in a large nonstick skillet. Add the eggs and season with salt and pepper. Cook over moderate heat, stirring gently with a wooden spoon, until the eggs are creamy, with large, soft curds, about 4 minutes. Stir in the chives and parsley and spoon the scrambled eggs onto warmed plates. Thinly shave the truffle all over the scrambled eggs and serve right away with the buttered brioche toast.