Torta (Mexican Sandwich)

For the meat

• 1 tablespoon olive oil
• ¼ onion, chopped (white or yellow)
• 2 cloves garlic, minced
• 2 ½ pounds chuck steak, diced into small cubes
• ½ teaspoon kosher salt, plus more as needed
• ½ teaspoon freshly ground black pepper
• 1 teaspoon chili powder
• ½ teaspoon garlic powder
• ½ teaspoon onion powder
• ¼ teaspoon ground cumin

For the guacamole

• 2 medium avocados
• 2 tablespoons lime juice (about 1 lime)
• ¼ white onion, chopped
• ¼ bunch cilantro, chopped
• ½ teaspoon kosher salt

For assembling

• 6 telera rolls, halved
• ¼ cup Butter, softened
• 1 (15-ounce) can refried beans, warmed
• 10-12 ounces queso fresco, sliced
• 2 Roma tomatoes, sliced
• ¼ iceberg lettuce, shredded
• ¾ cup salsa (chile de arbol salsa, salsa verde, or roasted tomato salsa)