1. Stir together the tartar sauce and crab boil seasoning in small bowl and set aside.
2. Tear 2 slices bread with crusts into small pieces and put into a bowl with the crab. Add the mayonnaise, Worcestershire, egg and a pinch of salt. Mix together gently, then form into 4 patties.
3. Preheat the broiler. Heat the butter in a large heavy skillet over medium-high heat until hot, add the crab burgers and cook, turning once, until golden brown, about 6 minutes total. Brush the remaining Pullman slices with oil on 1 side and place under broiler and toast to light golden brown.
4. Stir together shallot, lemon juice, and mustard with 1/4 teaspoon salt and 1/4 teaspoon pepper in large bowl. Whisk in 2 tablespoons oil, then add the frisee and toss to coat.
5. Place the Pullman toasts plain-side up and spread with tartar sauce. Top 4 bread slices with frisee, a crab burger and remaining bread slices. Serve any remaining frisee salad on the side.
Ian Knauer for Cooking Channel