Mom's Parsley Potatoes

 for 4

• 2 pounds red potatoes, scrubbed and cut into 1-inch pieces
• ¼ cup unsalted butter
• 1 cup chopped onion
• ½ teaspoon salt, or to taste
• ¼ teaspoon ground black pepper, or to taste
• ⅔ cup sour cream
• ⅓ cup shredded Gruyere cheese
• ⅓ cup chopped fresh parsley

1. Place potatoes into a large pot and cover with salted water; bring to a boil. 
2. Reduce heat to medium-low and simmer until barely tender, about 10 minutes.
3.  Drain and set aside.
4. Melt butter in the same pot over medium-low heat. 
5. Add onion, season with salt and pepper, and cook until onions are starting to turn clear, 2 to 3 minutes. 
6. Add potatoes, cover, and cook over low heat, stirring occasionally, until cooked through, about 5 minutes.
7. Remove from heat and stir in sour cream, Gruyere cheese, and parsley. 
8. Cover, and allow to sit until cheese is melted, about 5 minutes. 
9. Stir before serving.