Spicy chili burgers with onion rings

Ingredients:

• 1 large poblano pepper
• 1 package (400 g) of frozen onion rings
• 2 tsp chili powder
• 1 tsp ground cumin
• 0.5 cup hot ketchup
• 1 tbsp chopped fresh cilantro
• Grated zest and juice of 1 small lime
• 600 g lean ground beef
• 1 tbsp. vegetable oil
• 4 sesame seed buns, cut in half horizontally and toasted
• 4 small romaine lettuce leaves

Preparation:

1. Preheat the oven to broil. Place the poblanos on a baking sheet and broil, turning, until charred in spots, about 8 minutes. Transfer to a plate and let cool. Reduce the oven temperature and bake the onion rings according to package directions. Season with salt, pepper, and 1/4 teaspoon each of chili powder and cumin.
2. Meanwhile, in a small bowl, combine the ketchup, cilantro, a pinch of lime zest, and half the lime juice; season with salt and pepper to taste. Refrigerate until ready to use.
3. In a large bowl, combine the ground meat, 1/2 teaspoon lime zest, and the remaining 1 3/4 teaspoons chili powder and 3/4 teaspoon cumin. Form into four 2-cm-thick patties, seasoning both sides with salt and pepper. Heat the vegetable oil in a large nonstick skillet over medium heat. Add the patties and cook over medium heat until golden brown, 2-3 minutes per side, or medium-rare.
4. Peel and seed the roasted peppers and cut into strips. Place the patties on buns coated with ketchup sauce and top with lettuce and poblano peppers. Serve with onion rings and the remaining sauce.