4 tablespoons butter
1/3 cup all-purpose flour
1½ cups milk, warmed
1/8 teaspoon black pepper
Dash of brown nutmeg
¼ teaspoon salt
6 large egg yolks
6 large egg whites, room temperature
¼ teaspoon cream of tartar
1/8 teaspoon salt
1 cup (4 ounces) shredded cheddar cheese
2 tablespoons grated parmesan cheese
1/3 cup buttered, toasted white bread crumbs
Spinach and cheese filling
2 tablespoons butter
¼ cup minced onion
2 packages (10 ounces each) frozen chopped spinach, thawed and squeezed dry
¼ teaspoon salt
1¼ cups shredded cheddar cheese, divided
¾ cup sour cream
Heat oven to 425 degrees. Place a rack in the oven's middle position.
Butter a jelly roll pan and line with parchment or wax paper, leaving about 2 inches overhanging at each end. Butter and flour parchment.
In 3-quart saucepan, melt butter. Add flour and stir over moderate heat 2-3 minutes, until foamy but not browned. Remove from heat and add warmed milk all at once, whisking until blended. Return to heat and bring to a boil, stirring. Beat in pepper, nutmeg and ¼ teaspoon salt. Let cool 5 minutes. Whisk egg yolks one at a time into cream sauce.
Put egg whites into large mixing bowl. Beat whites until foamy; add cream of tartar and 1/8 teaspoon salt and beat until stiff. Fold one-quarter of the egg whites into cream sauce then fold in remaining whites. Fold in cheeses being careful not to stir the air out of the mixture.
Spread souffle mixture over wax paper-lined pan, making a rectangle about 12-by-17-inches. Bake in middle of oven for 12-15 minutes, until puffed and set. Remove from oven and sprinkle with bread crumbs. Lay parchment or wax paper, then aluminum foil over top and invert onto a cookie sheet. Let stand 5 minutes. Remove pan and carefully remove parchment. Some souffle will stick to the paper. If paper does not remove easily, return souffle to pan and place in oven for additional 3-4 minutes. The recipe can be made ahead up to this point. Wrap airtight and refrigerate or freeze. Bring to room temperature before continuing.
For the filling: In large skillet, melt butter and saute onion until transparent. Turn off heat. Add spinach, salt, ¼ cup cheddar cheese and sour cream. Stir until thoroughly combined.
Heat oven to 350 degrees.
Spread filling over egg layer and roll from long side, using wax paper and aluminum foil to help roll. Slide onto cookie sheet or oven proof serving platter. Sprinkle with 1 cup cheddar cheese, Roll can be refrigerated at this point; bring to room temperature before continuing.
Bake until heated through and cheese melts, about 15 minutes (or 40 minutes for refrigerated roll). Slice and serve.
"Crème de Colorado Cookbook" by the Junior League of Denver (1987)