If the chicken breast is thick, butterfly it and lightly pound to an even 1/2-inch thickness. Pat dry with paper towel. Season both sides with kosher salt, black pepper, and garlic powder.

Oil and grill

Brush the chicken lightly with olive oil. Preheat a grill or grill pan to medium-high (about 400°F / 200°C). Grill the chicken 4–5 minutes per side until cooked through and internal temperature reads 165°F (74°C).

Add cheese

During the last 1 minute of grilling, place the cheddar slice on the chicken and close the lid (or cover with a pan) so the cheese melts.

Cook bacon

While the chicken grills, cook the honey-cured bacon in a skillet over medium heat until crisp, about 3–5 minutes per side depending on thickness. Transfer to a paper towel-lined plate to drain.

Greens & Produce

Toss the baby arugula with lemon juice and a pinch of salt and pepper to brighten flavor. Pat the lettuce leaf dry and set aside. Slice the tomato into 2 even slices.

Sauce

In a small bowl, whisk together mayonnaise, Dijon mustard, honey, and freshly ground black pepper until smooth. Taste and adjust seasoning as desired.

Finish

Butter the cut faces of the brioche bun. Toast the bun, buttered side down, in a skillet over medium heat or on the grill until golden, about 1–2 minutes.

Assemble the cheeseburger: spread half the sauce on the bottom bun, place the grilled chicken with melted cheddar on top, add honey-cured bacon slices, layer the lettuce leaf and tomato slices, then the dressed baby arugula. Spread remaining sauce on the top bun and close the sandwich.

Serve immediately while warm.