01 -
Whisk together mayonnaise, mustard, and dried dill in a small bowl until fully incorporated. Cover and refrigerate until ready for sandwich assembly.
02 -
Melt 1 tablespoon of butter in a large skillet over medium heat. Add sliced onion and 1/2 teaspoon salt. Sauté, stirring frequently, until the onion is softened and edges are golden-brown, about 6-8 minutes. Transfer onions to a separate bowl and set aside.
03 -
Add 1 tablespoon of butter to the skillet and reduce heat to medium-low. Pour in the beaten eggs and cook, gently stirring, until softly scrambled. Divide the eggs into two even portions and set aside.
04 -
In a bowl, toss shaved steak with Worcestershire sauce and Montreal steak seasoning until fully coated. Melt the remaining tablespoon of butter on the skillet over medium-high heat. Spread the steak evenly and cook, undisturbed, for 2 minutes. Stir and cook until just browned, about 2-3 more minutes.
05 -
Return the cooked onions to the skillet with the steak. Stir to combine. Form the steak and onion mixture into two even piles. Place a slice of American cheese over each pile and allow to melt, about 1 minute.
06 -
Toast bagel halves on a clean skillet or in a toaster until golden-brown.
07 -
Spread a generous layer of the signature sauce on each cut bagel surface. Place a scrambled egg portion on the bottom half of each bagel, then top with the steak, onion, and melted cheese mixture. Close with the top bagel halves and serve immediately.