French Onion Shepherd's Pie

Ingredients (11)

• + 5 medium potatoes, peeled and cubed add to pantry
• + 1 cup shredded Cheddar cheese, divided add to pantry
• + ⅛ cup milk add to pantry
• + 1 green onion, chopped add to pantry
• ✓ 1 tablespoon salted butter
• + 1 pound ground beef add to pantry
• + 2 tablespoons all-purpose flour add to pantry
• ✓ ¼ teaspoon ground black pepper, or more to taste
• + 1 (10.5 ounce) can condensed French onion soup add to pantry
• ✓ ¼ cup water
• + 1 cup frozen peas add to pantry