Preheat the oven to 375.
Grease and 8-cup casserole dish.
Brown the beef with the onion in a large skillet over medium heat, about 10 minutes.
Drain the grease.
Combine the cream cheese, soup, milk, salt, and ketchup in a medium bowl. Stir to blend.
Add to the ground beef and stir well. Spoon into the prepared dish.
Bake for 20 minutes.
Place the unbaked biscuits on top.
Return the casserole to the oven and bake until the biscuits are browned and cooked through, 10 - 15 minutes.