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Sweet Potato Gratin with Smoked Gouda and Rosemary
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3 from 1 vote

Sweet Potato Gratin with Smoked Gouda and Rosemary

A savory sweet potato recipe that will have them coming back for thirds, this Sweet Potato Gratin with Smoked Gouda and Rosemary is loaded with 3 kinds of cheese, fresh rosemary and creamy sweet potatoes. Perfect for Thanksgiving!
Prep Time15 minutes
Cook Time1 hour 15 minutes
Total Time1 hour 30 minutes
Course: Dinner, Side Dish
Keyword: asiago cheese, smoked gouda, sweet potatoes
Servings: 10

Equipment

  • 9"x13" large ceramic baking dish
  • aluminum foil
  • mandoline slicer (optional but recommended)

Ingredients

  • 3 lbs sweet potatoes- peeled, rinsed, and thinly sliced into ⅛” rounds  (mandoline slicer preferred)
  • 4 tablespoon butter
  • 2 cloves garlic, minced or pressed
  • 1 small red onion, finely diced
  • 1 tablespoon all-purpose flour
  • 1 cup heavy cream
  • 1 cup half and half, or whole milk
  • ½ tablespoon finely chopped fresh rosemary leaves
  • 1 teaspoon smoked paprika
  • ¼ teaspoon ground sage 
  • ½ teaspoon Diamond Kosher salt
  • ¼ teaspoon freshly ground black pepper
  • ¼ teaspoon freshly grated nutmeg
  • ⅓ cup grated asiago cheese 
  • 1 cup smoked gouda cheese, shredded (divided)
  • 1 cup Colby Jack cheese, shredded (divided)

Instructions

  • Preheat oven to 400 degrees f.
    2. Melt butter in a large saucepan over medium heat.
    3. Add garlic and onions, and cook stirring occasionally until softened, about 5 minutes.
    4. Add the flour and stir well to combine. Cook 1 minute, stirring occasionally.
    5. Slowly whisk in the heavy cream ad half and half to combine.
    6. Bring heat to medium-high and cook 3-4 minutes, stirring occasionally until slightly thickened, and starting to bubble. Immediately turn off heat.
    7. Stir in asiago cheese, fresh chopped rosemary, smoked paprika, ground sage, salt, pepper and nutmeg. Remove from heat and allow to cool to room temperature.
    8. While your sauce cools, peel potatoes, and and slice thinly (about ⅛”) with a mandolin slicer or sharp knife.
    9. Grease a baking dish with butter or cooking spray, and arrange the potatoes in a circular pattern. (If lying flat, set aside and toss well with prepared sauce before adding to the dish).
    10. Once sauce is fully cooled, stir in half of the Colby Jack cheese and half of the smoked gouda cheese to combine. It will not melt, and that’s ok!
    11. Pour sauce over potatoes in casserole dish (or stir together with potatoes if lying flat), and top with remaining Colby Jack and Smoked gouda cheeses.
    12. Cover dish tightly with foil, and bake in preheated oven for 45 -50 minutes, or until potatoes are tender and easily pierced with a a pairing knife (it should slide through with no resistance).
    13. Once potatoes are tender, remove foil and bake an additional 15-20 minutes, until golden brown. Let rest 10-15 minutes, and serve warm.
    Note: If you want extra browning, bake a bit longer uncovered or briefly broil if your dish is broiler safe and keep a close eye on it.

Notes

Originally published on 11/02/2021, updated on 08/25/25.