In a large skillet, melt 3 tablespoons butter over medium-low heat. Add onion and cook to soften, about 3 to 4 minutes.
Add potatoes and chicken broth. Bring to a boil, cover, and cook over medium low heat for 8 minutes.
Stir in the green beans and continue to cook covered until the beans and potatoes are tender, about 8 to 10 minutes more. Remove the lid and simmer until most of the water is evaporated.
Stir in remaining 1 tablespoon butter and bacon bits. Season with salt and pepper to taste.
Notes
To crisp the bacon bits, place them on a paper towel lined plate, and microwave for 30 to 40 seconds.