In a large skillet cook the ground beef with onions; cook stirring until meat is no longer pink. Drain all fat well. Continue to cook until the meat is well browned, about 4-5 minutes longer. Pour contents of taco seasoning pack into meat and add water as directed on the package. Continue to cook according to package directions.
Add in the refried beans and salsa. Cook, stirring occasionally, until heated through.
Add in 3/4 cup grated cheddar cheese; stir until melted.
Place the tortilla chips on a large serving platter.
Top with ground beef mixture, then sprinkle the top of the HOT ground beef mixture with about 1-1/2 cups (or to taste) grated cheddar cheese.
Top with sour cream, green onions, chopped tomatoes, shredded lettuce, and sliced black olives.