Prep your base: Chop the romaine or iceberg and set aside in a large bowl.
If using cauliflower rice or grains, warm them and fluff with a fork.
Make the sauce: In a small bowl, mix 2 tablespoons mayonnaise (or Greek yogurt), 1 tablespoon ketchup, 1 teaspoon mustard, 1 teaspoon apple cider vinegar, and a pinch of salt and pepper. Adjust to taste. Thin with a splash of water if needed.
Season the beef: In a separate bowl, combine 1 teaspoon kosher salt, 1/2 teaspoon black pepper, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1/2 teaspoon smoked paprika, and a pinch of chili powder.
Sprinkle over the ground beef and toss gently to distribute.
Sauté the aromatics: Heat a large skillet over medium-high. Add 1 teaspoon oil and the diced onion. Cook 3–4 minutes until softened and lightly golden.
Brown the beef: Add seasoned beef to the skillet.
Break it up with a spatula and cook until well browned, 6–8 minutes. If there’s extra fat, drain it. Taste and adjust salt and pepper.
Add burger-style touches: Stir in 1–2 teaspoons mustard and 1–2 tablespoons ketchup to the beef for that classic flavor.
Cook 1 minute to warm through.
Prep the toppings: Halve cherry tomatoes, chop pickles, slice red onion and jalapeño, and dice avocado. Shred cheese if not pre-shredded.
Assemble bowls: Add lettuce (and optional warm base) to each bowl. Spoon on the hot beef.
Top with tomatoes, pickles, red onion, jalapeño, avocado, and a generous sprinkle of cheddar.
Finish with sauce: Drizzle the burger sauce over the top. Sprinkle sesame seeds if you like.
Serve: Add extra ketchup, mustard, or hot sauce at the table. Eat right away while the beef is warm and the greens are crisp.