In 10-inch skillet, cook beef over medium-high heat 5 to 7 minutes, stirring frequently, until brown; drain.
Stir in milk, hot water, beer, uncooked pasta and sauce mix (from Hamburger Helper box). Heat to boiling, stirring occasionally.
Reduce heat; cover and simmer about 10 minutes, stirring occasionally, until pasta is tender. Remove from heat; uncover.
Top with 1/2 cup of the cheese, the bacon and onions. Sprinkle remaining 1/2 cup cheese on top. Cover; let stand 5 minutes (sauce will thicken as it stands).