1 1/2 cups butter or margarine, cut into chunks
6 large egg yolks
1/4 cup lemon juice
2 Tbs Dijon mustard
6 English muffins
6 rashers bacon
Baby spinach leaves (optional)
Sliced avocado (optional)
In a microwave-safe 2-cup glass measure in a microwave oven at full power, or in a pan over medium-high heat, melt butter until bubbling.
Meanwhile, in the bottom of a double boiler or in a pan, bring 1 inch water to a simmer over high heat; adjust heat to maintain simmer.
Put yolks, lemon juice, and mustard in the top of the double boiler or in a round-bottomed bowl. Nest the container over simmering water and whisk to blend.
Whisking, add butter in a slow, steady stream, taking about 1 1/2 minutes. Whisk until sauce reaches 60 C; adjust heat to maintain temperature (remove from simmering water if necessary) and continue to whisk for 3 minutes. Immediately remove from simmering water. Serve hollandaise hot, warm, or at room temperature.
Split muffins in half horizontally and arrange in a single layer, cut sides up, on a baking sheet. Lay bacon slices in a single layer in a pan.
In a 230 C oven, bake muffins and bacon until browned, 5 to 7 minutes.
Place 2 muffin halves, cut sides up, on each plate. Lay 1 bacon slice on each muffin half; set 1 egg on each slice of bacon. Spoon hollandaise equally over portions.
Serve with baby spinach leaves and sliced avocado.