Sarah's Spinach Side Dish

Ingredients (6)

• + 1 tablespoon whipped butter add to pantry
• + 1 tablespoon all-purpose flour add to pantry
• + 1 pinch garlic salt add to pantry
• ✓ 1 pinch kosher salt
• + ¼ cup low-fat milk add to pantry
• + 1 (10 ounce) package frozen chopped spinach, thawed and squeezed dry add to pantry