01 -
Heat olive oil in a skillet over medium-high heat. Add lean ground beef and diced onion, cooking until the beef is browned and onions are translucent.
02 -
Stir in minced garlic and cook for an additional 30 seconds until aromatic.
03 -
Transfer the cooked beef mixture to a slow cooker. Season with salt and black pepper. Stir in cubed processed cheese, ketchup, and mustard until combined.
04 -
Cover and cook on low for 3 to 4 hours, stirring occasionally to ensure even melting and flavor distribution.
05 -
Scoop the cheesy beef mixture onto the burger buns. Top each with a cheese slice and pickles before serving.