Combine all the ingredients and whisk until blended. Pour into two large buttered custard cups filling them 3/4 full. Place on a rack in a pan and fill so that the water reaches the level of the vegetable.
Bake 20 minutes at 325F or until an inserted knife comes out clean. The timbales can be made in advance and reheated. Turn out onto a heated plate. Garnish with Hollandaise.
HOLLANDAISE SAUCE: Whisk egg yolk, cream, and lemon juice over moderate heat for about one minute or until sauce just begins to thicken. Take from heat and whisk in butter. Return to heat for a moment to thicken, whisking hard. Season with salt and cayenne. Sauce can be made in advance and reheated in a microwave oven or over warm water; however, if ingredients are assembled, it can be made easily at the last minute.