Start by heating the olive oil in a frying pan over medium heat. Add the ground beef, breaking it up with a spatula. Cook until browned, about 8-10 minutes.
In a large bowl, combine the cherry tomatoes, avocado, red onion slices, and chopped lettuce. Top the mixture with the cooked beef.
Sprinkle the shredded cheddar cheese over the beef while it's still warm. Drizzle mustard and ketchup over the top.
Give the bowl a final stir to combine all ingredients evenly. Serve immediately while the beef is warm and the cheese is melted.
Notes
Store leftovers in airtight containers in the refrigerator for up to three days.