Salade Lyonnaise Sandwich

1/4 pound pork belly (or thick-cut bacon), cut into 1-inch cubes 
1 shallot, minced
1 tablespoon red wine vinegar
1 tablespoon Dijon mustard
White Vinegar
4 large eggs
2 1/2 cups of frisée salad, washed and torn into bite-size pieces 
Freshly ground pepper
4 brioche buns, slice in half
1 large tomato, sliced 

1. Place cubes of pork belly in a skillet, set over medium heat and cook until bacon is crisp all over, about 10 minutes. Add minced shallot and cook until softened, a minute or two. Add red wine vinegar and mustard to the skillet and bring just to a boil, stirring, then turn off heat.

2. Meanwhile, bring about four inches of salted water to a boil in a medium pot, then lower heat to barely bubbling. Add a splash of white vinegar, which will aide the egg whites in coagulating. Take a spoon and swirl it around in the water, in one direction, creating a whirlpool. One at a time, break eggs into a shallow bowl and slip them into the center of the bubbling, swirling water. Cook eggs for about 3 to 4 minutes, just until the white is set and the yolk has filmed over. Remove each egg with a slotted spoon and drain briefly on paper towel.

3. Put frisée in a medium bowl. If necessary, gently reheat dressing, then pour over greens (they should wilt just a bit), toss and season with salt and pepper to taste. 

4. Preheat oven to 300F. To assemble the sandwiches, slice buns in half and transfer to a warmed oven or conventional oven. Bake until just warm. Remove and lay out. Place a few slices of tomatoes on each bottom half and top with a pinch of salt. Top with a small handful of the frisée mixture, poached egg and garnish with salt and pepper. Serve immediately.  

Recipe adapted from Mark Bittman's Salade Lyonnaise

Yields 4 sandwiches