INGREDIENTS
10
thin slices Pepper-crusted pastrami, good-quality
1/2 tsp
Garlic
1 tsp
Thyme, leaves
2
Yellow or walla walla onions, medium
1
Egg yolk, large
1 1/3 tbsp
Dijon-style mustard
1 1/2 tsp
Lemon juice, fresh
2
Kosher salt
1/4 tsp
Red pepper flakes
1/2 cup
Canola oil
4
Pretzel rolls or other sandwich rolls
6 tbsp
Butter, unsalted
4 oz
Gruyere cheese