In a double boiler over med./low heat, add egg yolks, mustard, lime juice and hot sauce. With a very THIN ribbon, whisk in melted butter, slowly a tablespoon at a time. Whisk until smooth and incorporated. Take off heat and cover to keep warm.
In a large sauce pan, bring 6 cups of water and vinegar to a gentle roll over med. heat. Add eggs one at a time slowly . Cook eggs for approximately 4 minutes for solid whites, and runny yolks.
At same time, brown Canadian bacon slices in pan, and lightly brown English muffin halves in toaster or broiler.
Assemble, English muffin, Canadian bacon, poached egg, and cover with Hollandaise sauce. Top with scallions, and sprinkle with cayenne pepper to taste. Garnish with cilantro sprigs on top.
Options: Try with a thin slice of tomato, or onion, or both. Try cappocola ham, or smoked salmon in place of Canadian bacon.