Cheesy Mashed Potato Soup

This is the genius use for leftover mashed potatoes hiding in the fridge after a holiday. The pre-cooked starch melts into hot milk and sharp cheddar to produce a thick, creamy soup in 20 minutes flat. No peeling, no boiling, no cubing. The hard work was done last night.

The technique is essentially a cheese sauce that gets thinned with mashed potatoes instead of thickened. Start with the onion in butter or margarine, sprinkle flour to build a quick roux, whisk in milk, then fold in the cheese spread and potatoes. Each step takes a minute or two.

Sharp cheddar cheese spread (the jarred kind) was the original ingredient, designed for this kind of weeknight recipe. If you don’t have it, substitute 1 cup grated sharp cheddar plus a tablespoon of cream cheese for similar texture and flavor.

Stir constantly while the cheese melts. The milk-cheese mixture scorches fast on the bottom of the pot, and once it tastes burned, no amount of pepper or salt will save it. Medium heat with a wooden spoon doing slow figure-eights is the right rhythm.

Mashed potato thickness varies. If your leftover potatoes were heavy on butter and cream, you’ll need a little more milk than the recipe calls for. Adjust to your preferred soup consistency.

Pro Tips

• Whisk the flour into the melted butter for a full minute before adding milk to avoid raw flour taste.
• If the soup gets too thick, thin with warm milk or chicken stock, a splash at a time.
• Garnish with crumbled bacon, chopped chives, and an extra sprinkle of cheese for loaded-potato vibes.
• Use a hand blender to smooth out any potato lumps for a more refined texture.

Variations

• Stir in a half cup of cooked broccoli florets for broccoli-cheddar potato soup.
• Add a teaspoon of Dijon mustard to cut the richness.
• Top with crispy fried shallots for a textural contrast.