- 23 cup sugar, plus additional for coating gratin dish
- 1 13 cups whole milk
- 8 tablespoons unsalted butter
- 12 cup all-purpose flour
- 4 large eggs, separated, left a room temperature for 30 minutes
- 12 cup Grand Marnier
- 4 large egg whites, left a room temperature for 30 minutes
- 12 teaspoon salt
- 12 teaspoon cream of tartar
- Put a rack in middle of oven and preheat to 400F.
- Butter gratin dish (see above) and sprinkle with sugar, knocking off excess.
- Bring milk just to a simmer in a small saucepan.Remove from heat.
- Melt butter in a 2 to 3 quart saucepan over low heat.
- Stir in flour and cook, stirring, for 5 minutes to make roux.
- Remove pan from heat and add milk in a steady stream, whisking constantly, then add remaining 2/3 cup sugar, whisking vigorously.
- Cook mixture over low heat, whisking, until smooth, about 2 minutes.
- Remove pan from heat and add egg yolks one at a time, whisking after each addition until incorporated.
- Slowly whisk in Grand Marnier.
- Cover mixture with a buttered round of wax paper and cool to room temperature.
- Beat 8 whites with salt in a large bowl with an electric mixer at medium speed until frothy.
- Add cream of tarter, increase speed to high, and beat until whites form stiff peaks.
- Stir one quarter of whites into yolk mixture to lighten it, then gently but thoroughly fold mixture into remaining whites.
- Reserve 1 cup of mixture and transfer remainder to gratin dish.
- Mound reserved mixture in center.
- Bake souffle until puffed and golden, 25 to 30 minutes.
- Serve immediately.