In a small bowl set over a pan of barely simmering water whisk egg yolks with lemon juice until pale yellow and foamy. Pour in butter in a thin stream, whisking constantly, until sauce emulsifies. Season to taste with Tabasco, salt and white pepper. Keep warm in bowl over hot, not boiling, water. Yield: about 1 cup
Preheat oven to 375 degrees F. Butter a medium gratin dish with 1 teaspoon of the butter. In a food processor, fitted with a metal blade, combine the chopped morels, shallots and garlic. Pulse the mixture, several times to chop coarsely. In a large saute pan, over medium heat, melt the remaining butter. Add the mushroom mixture. Season with salt and pepper. Saute for 2 minutes. Remove from the heat and stir in the bread crumbs and cheese. Season to taste with truffle oil. Cool completely. Make a small slit on 1 side of each of the whole morels. Stuff each with about 2 teaspoons of the stuffing. Press to close. Place the stuffed morels in the prepared pan. Pour the Hollandaise Sauce over the morels. Place on the next to the top rack in the oven. Bake until the top is golden, about 10 to 12 minutes. Remove from the oven. Spoon the morels onto serving plates. Garnish with shaved truffles and chives.