Roasted Poblano Smash Burgers on the Traeger
Inspired by In-N-Out’s legendary 4x4, this burger layers thin, crispy smash patties with smoky roasted poblanos, melty pepper jack cheese, creamy avocado, sweet-spicy candied jalapeños, and tangy aioli. Perfectly balanced and packed with flavor, it’s a backyard burger worth repeating.
Equipment
- Traeger Flatrock griddle or cast iron skillet
- Burger Smasher or cast-iron press (see blog for alternatives)
- Knife and cutting board
- Mixing bowls
- Tongs or spatula
Ingredients
- 8 oz 80/20 ground beef divided into four 2-ounce balls
- 4 whole poblano peppers roasted, peeled, and chopped
- 4 slices pepper jack cheese
- 2 potato buns
- 1 avocado smashed
- 2 tbsp mayo 1 tbsp for aioli + about 2 tsp for bun toasting
- 1 tbsp spicy taco sauce or hot sauce for aioli
- 2 –3 tbsp homemade candied jalapeños or store-bought
- Pickles optional for extra tang
- Tex-Mex seasoning blend
Instructions
- Roast the Poblanos – Grill, torch, or broil whole poblanos until skins are blistered and black. Transfer to a bowl, cover, and steam for 10 minutes. Peel skins, remove seeds, and chop finely.
- Prep the Beef – Form the ground beef into four loose 2-ounce balls. Season lightly with Tex-Mex seasoning.
- Smash the Patties – Preheat your griddle to medium-high. Place a small pile of chopped poblanos on the hot surface, set a beef ball on top, and smash firmly with a burger press or spatula. Cook for 1–2 minutes until the edges are crispy.
- Flip & Add Cheese – Flip the patties, top with pepper jack cheese, and let melt while the second side finishes cooking.
- Toast the Buns – Spread about 1 tsp mayo on the cut side of each bun half. Place mayo-side down on the griddle and toast until golden brown.
- Make the Aioli – In a small bowl, mix 1 tbsp mayo with 1 tbsp spicy taco sauce or hot sauce. Stir until smooth.
- Assemble the Burger – Spread smashed avocado on the bottom bun. Layer two patties, candied jalapeños, pickles (if using), and a drizzle of aioli. Repeat with the final two patties. Top with the bun and serve hot.
Notes
Roast extra poblanos and freeze for quick future meals.
Smash the patties immediately after placing them on the griddle for the best crust.
Layer cheese between patties for extra melt and gooeyness.
Try Anaheim peppers for a milder heat or Oaxaca cheese for a different melt profile.