Place ground bison in a large bowl. Add fine dry breadcrumb, egg yolk, Worcestershire sauce, sea salt, black pepper, and garlic powder. Using clean hands, gently combine until just mixed — do not overwork (about 20–30 seconds). Divide mixture into 4 equal portions (about 4 oz each) and gently form into patties roughly 3/4 inch thick and slightly wider than the buns. Press a slight dimple into the center of each patty with your thumb to help them cook evenly.

Rest patties

Transfer the formed patties to a plate and refrigerate for 15 minutes to help them firm up (this helps retain juices while cooking).

Preheat and oil cook surface

About 10 minutes before cooking, preheat a cast-iron skillet or heavy-bottomed pan over medium-high heat (or preheat a grill to medium-high, about 400°F / 200°C). Lightly brush the pan or grates with the olive oil to prevent sticking.

Cook patties

Place patties on the hot skillet or grill. Cook for 3 to 4 minutes on the first side without moving, until a brown crust forms. Flip once and cook another 2 to 3 minutes for medium-rare to medium (internal temperature 130–140°F / 54–60°C). If you prefer medium-well, cook 3 to 4 minutes on the second side. In the last 30–45 seconds of cooking, place a slice of cheddar on each patty and cover the pan or close the grill lid to melt the cheese.

Rest cooked patties

Remove patties to a plate and loosely tent with foil. Rest for 3 to 5 minutes to allow juices to redistribute.

Toppings & Buns

Prepare vegetables

While patties rest, thinly slice the red onion into rings and slice the tomato into 4 even slices. Wash and dry lettuce leaves. Set out pickle slices.

Toast buns

Spread softened butter on cut sides of the buns. Heat a clean skillet or griddle over medium heat and toast cut sides down for 1 to 2 minutes until golden and lightly crisp. Alternatively, toast on the grill for 30–60 seconds. Remove from heat.

Assemble burgers

Spread about 1 tablespoon mayonnaise on the bottom half of each bun, then 1/2 teaspoon mustard and 1 teaspoon ketchup (adjust to taste). Place a lettuce leaf on the sauced bottom bun, add the cheesy bison patty, then a tomato slice, 2–3 rings of red onion, and two pickle slices. Top with the bun crown.