6 slices thinly sliced beefsteak or heirloom tomatoes
6 ounces thinly sliced smoked salmon
BAGEL ÔCROUTONS’: Preheat grill according to manufacturer’s directions. Place butter in cast iron skillet over medium heat and melt. Cut bagel in half crosswise and then into 1/4-inch thin coins. Add bagel coins to skillet along with salt, garlic powder and pepper; toss to coat bagel with seasonings and ensure that bagel coins are in single layer. Cook the bagel coins for 3-4 minutes or just until golden brown. Flip coins and cook for additional 2-3 minutes. Remove from heat and place on a plate in a single layer to preserve crispness. [This step may be done 1-2 days ahead; after cooling in a single layer, store in an airtight container at room temperature.]
BAGEL SEASONING: In a small mixing bowl, mix sesame seeds, poppy seeds, onion flakes, garlic flakes, salt and pepper together. Store in a tightly sealed container. Shake container before using.
CREAM CHEESE SPREAD: In a small mixing bowl, thoroughly combine cream cheese, sour cream, green onions, capers, Worcestershire sauce, salt and pepper. [This step can be done 1-2 days ahead; store in a tightly sealed container in the refrigerator. Bring to room temperature before using.]
BURGERS: In a large mixing bowl, using clean hands, mix together ground chuck, ribeye, short rib and brisket together with 1/4 Cup of BAGEL SEASONING. Divide mixture into 6 equal portions and form into patties. Use your thumb to make a large indent in the center of each patty (to prevent the center from puffing up as it cooks). Sprinkle both sides of each patty with salt and pepper. Place burger patties on preheated grill; cook for 3 minutes. Flip burgers and cook for additional 4 minutes.
Spread cut side of each bun with 1 tablespoon butter, sprinkle with scant 1/2 teaspoon of BAGEL SEASONING and place buttered side down on hot grill. Grill 1-2 minutes, or just until toasted light golden brown.
Spread each bun half with 1 tablespoon of cream cheese mixture. Place thinly sliced red onion, tomato and smoked salmon on each bottom bun half, and then place one burger on top. Place 2-4 toasted bagel coins on top of burger and top with bun half; serve immediately.