Heat a grill pan or large skillet over medium-high heat.

Brush both sides of each portobello mushroom cap with olive oil, and season with salt and pepper.

Place them in the pan, and cook for 7 to 8 minutes on each side.

Remove them from the heat, and set aside.

Bring a large saucepan of water to a low simmer.

Add the white vinegar. Crack 1 egg into a small dish. Use a large spoon to swirl the water into a slow whirlpool. Carefully slide the egg into the water and, without hitting the egg, continue the swirling motion with the spoon. Allow the egg to cook for a minute or two, until the white has set. Carefully scoop the egg out and place it on a paper towel–lined plate.

Repeat with the remaining eggs.

In the skillet you used for the mushrooms, heat the Canadian bacon over low heat, about 2 minutes per side.

Place a heatproof bowl over a pot of simmering water (don’t let the bowl actually touch the water).

Put the egg yolks and lemon juice in the bowl, and quickly whisk them together until the mixture becomes frothy and starts to expand, about 2 minutes. Slowly drizzle the melted butter in while stirring, and continue to whisk until the sauce has doubled in size, 5 to 6 minutes.

Remove from the heat, and add the cayenne and salt.

Serve immediately or keep warm until ready to serve. 〉