Combine the mayonnaise and harissa in a small bowl and stir until blended. Set aside.
Cut the bacon in half crosswise, arrange in a medium skillet, and put the skillet over medium heat. Cook, turning the bacon frequently, until cooked through and crispy but still a little chewy, about 8 minutes. Transfer to a paper towel–lined plate and set aside.
Bring about 4 cups of water to a boil in a small saucepan. Lower the
heat to a bare simmer and add
1 tablespoon of the vinegar. Crack an egg
into a small cup or ramekin and, holding the cup just above the surface
of the water, carefully pour the egg into the water. Repeat with the
second egg. Cook the eggs until the whites have cooked through but the
yolk is still runny, 2 to 3 minutes. (To check, carefully lift an egg
out of the water with a slotted spoon. Prod the white—it should feel
firm and bouncy all the way through.) With a slotted spoon, transfer the
eggs to another paper towel–lined plate.
In a small bowl, combine the frisee or radicchio, the remaining 1 teaspoon vinegar, the shallot, and the olive oil. Sprinkle with a pinch of salt and pepper and toss to blend.
Toast or grill the bread to your liking, then spread the mayo evenly over two pieces. Top with the bacon, tomato, frisee, and egg. Sprinkle the egg with a little salt and pepper, then top with the other two pieces of bread.
Serve right away (with plenty of napkins).
Photo: France Ruffenach © 2011
Reprinted with permission from Bi-Rite Market’s Eat Good Food by Sam Mogannam & Dabney Gough, copyright © 2011. Published by Ten Speed Press, a division of Random House, Inc.