Lay the flour tortillas flat on a clean surface.
Spread 1/4 cup of sour cream evenly over each tortilla.
In a bowl, mix the cooked ground beef with taco seasoning, if using, and season with salt and pepper.
Evenly distribute the seasoned ground beef over the sour cream on each tortilla.
Sprinkle 1/2 cup of shredded cheddar cheese on top of the beef on each tortilla.
Add shredded lettuce and diced tomatoes on top of the cheese.
Starting from one edge, carefully roll each tortilla tightly to form a log.
Once rolled, slice each tortilla into 1-inch pieces.
Arrange the roll-ups on a serving platter and drizzle with salsa.
