Preheat the oven to 275 degrees F.

Saute butter and shallots until soft. Add Champagne and simmer until reduced by half. Remove from heat and add tarragon. Steep for 5 minutes.

Meanwhile, in a medium saucepan, cook the cream with the salt and pepper over moderate heat until the surface begins to shimmer.

Whisking constantly, pour warm cream mixture into the beaten egg yolks. Add the Champagne mixture. And pour through a very fine sieve into 4 (4-ounce) creme brulee dishes.

Place the dishes into a shallow baking dish large to hold them without crowding. Place the dish on the middle rack oven. Carefully fill the baking dish with very hot tap water so it comes halfway up the sides of the filled dishes.

Bake for about 45 minutes, or until the custard is set in the center. Remove the custards to a wire rack to cool. Refrigerate for at least 1 hour, or until ready to use.

When ready to serve, preheat the broiler. Generously sprinkle the top of each chilled custard with an equal portion of the sugar in the raw, taking care to cover all of the custard, so that it gives an even finish.

Place the chilled creme brulee dishes under the preheated broiler and broil for about 2 minutes, or until the tops are crackling brown. Remove from the broiler and serve immediately with creme fraiche.