Prep the avocados: Slice avocados in half lengthwise and remove the pits.
Scoop out a spoonful from each half to create a slightly larger well. Reserve the extra avocado for the sauce or topping.
Make a quick burger sauce: In a small bowl, mix mayonnaise, mustard, and ketchup. Stir in a pinch of smoked paprika if you like.
Set aside.
Cook the beef: Heat oil in a large skillet over medium heat. Add onion and cook 3–4 minutes until softened. Stir in garlic for 30 seconds, then add ground beef.
Season and brown: Break up the beef with a spatula.
Sprinkle with salt, pepper, smoked paprika, and onion powder. Cook until browned with no pink remaining, about 6–8 minutes. Drain excess fat if needed.
Enrich the flavor: Stir in tomato paste until it coats the beef and turns slightly darker, 1 minute.
Taste and adjust seasoning.
Add cheese: Sprinkle shredded cheese over the beef. Turn off the heat and let it melt. You can cover the skillet for 1–2 minutes to help it along.
Assemble: Place avocado halves on a platter.
Add a small pinch of salt to each. Spoon the cheesy beef into each avocado well, packing it gently.
Top it like a burger: Add diced pickles and shredded lettuce. Drizzle with burger sauce.
Use any reserved avocado to dot over the top or mash into the sauce.
Garnish and serve: Finish with chopped chives or parsley for color. Serve warm, with extra sauce on the side.