Martha's Hamburger Gravy

2 lbs. ground beef
1 onion, diced
6 Tbs flour
2 beef bouillon cubes
2 tablespoons Worcestershire sauce
4 cups milk

Directions
In a large skillet, brown ground beef, onion, salt and pepper, over medium-high heat until beef is thoroughly cooked. Add the bouillon cubes half-way thru browning. Stir in Worcestershire sauce. 

Sprinkle with flour and stir until beef is coated and starts to brown on bottom of pan. Stir in milk and use a spatula to scrape the browned bits off the bottom. Cook and stir 4 to 6 minutes or until mixture boils and thickens, stirring frequently.  Add salt and pepper to taste.