Preheat your oven to broil at high temperature, place the poblano peppers on a baking sheet and broil for 15-20 minutes, turning occasionally until skins are blackened. Transfer to a covered bowl to steam for 30 minutes.

In a mixing bowl, combine softened cream cheese, shredded cheddar cheese, garlic powder, salt, pepper, and diced chives. Blend until smooth and creamy.

Preheat your grill to 500-550°F, season burger patties with your favorite burger seasoning. Grill the patties for about 1.5 minutes per side, adding cheese mixture on top after flipping. Cook for another 2 minutes until cheese is melted.

Slice brioche buns and place cut-side down on the grill. Toast for 2-3 minutes until golden brown.

Assemble your burger with a grilled patty on the bottom half of each toasted bun, topped with roasted poblano pepper. Serve immediately.