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Sweet Potato Gratin with Smoked Gouda and Rosemary Recipe

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3.9 from 3 reviews

This Sweet Potato Gratin with Smoked Gouda and Rosemary is a rich and comforting casserole perfect for holiday dinners or a cozy weeknight meal. Thinly sliced sweet potatoes are layered and baked in a creamy, flavorful sauce infused with garlic, fresh rosemary, smoked paprika, and nutmeg, then topped with a blend of smoked gouda, Colby Jack, and Asiago cheeses for a beautifully golden and cheesy crust.

Ingredients

Sweet Potato Base

  • 3 lbs sweet potatoes, peeled, rinsed, and thinly sliced into 1/8” rounds (mandoline slicer preferred)

Sauce

  • 4 tbsp butter
  • 2 cloves garlic, minced or pressed
  • 1 small red onion, finely diced
  • 1 tbsp all-purpose flour
  • 1 cup heavy cream
  • 1 cup half and half or whole milk
  • 1/2 tbsp finely chopped fresh rosemary leaves
  • 1 tsp smoked paprika
  • 1/4 tsp ground sage
  • 1/2 tsp Diamond Kosher salt
  • 1/4 tsp freshly grated nutmeg
  • 1/4 tsp freshly ground black pepper (added based on instructions)

Cheese

  • 1/3 cup grated Asiago cheese
  • 1 cup smoked gouda cheese, shredded (divided)
  • 1 cup Colby Jack cheese, shredded (divided)

Instructions

  1. Preheat the oven: Set your oven to 400°F (204°C) to prepare for baking the gratin.
  2. Prepare the sauce base: In a large saucepan, melt the butter over medium heat. Add the minced garlic and diced red onion and cook, stirring occasionally, for about 5 minutes until softened and fragrant.
  3. Make a roux and add dairy: Sprinkle the flour over the onion mixture and stir well to combine. Continue cooking for 1 minute to eliminate the raw flour taste. Slowly whisk in the heavy cream and half and half. Increase heat to medium-high and cook for 3-4 minutes, stirring occasionally, until the sauce thickens slightly and just starts to bubble. Then immediately turn off the heat to prevent curdling.
  4. Flavor the sauce: Stir in the grated Asiago cheese, chopped fresh rosemary, smoked paprika, ground sage, kosher salt, freshly ground black pepper, and freshly grated nutmeg. Mix thoroughly. Remove the sauce from heat and allow it to cool to room temperature.
  5. Slice the sweet potatoes: While the sauce cools, peel and thinly slice the sweet potatoes into 1/8” thick rounds using a mandoline slicer or a sharp knife to ensure uniform cooking.
  6. Prepare the baking dish and assemble: Grease a baking dish generously with butter or cooking spray. Arrange the sweet potato slices in a circular pattern in the dish. Alternatively, for easier serving, you may toss the sweet potato slices with the sauce before transferring the mixture into the baking dish.
  7. Incorporate cheeses into sauce: Once the sauce has cooled completely, stir in half of the shredded Colby Jack cheese and half of the shredded smoked gouda cheese. The cheese will not melt fully into the sauce, which is expected.
  8. Combine potatoes and sauce: Pour the sauce evenly over the arranged sweet potatoes in the casserole dish, or mix together if you chose to toss before layering.
  9. Add remaining cheese topping: Sprinkle the remaining Colby Jack and smoked gouda cheeses evenly over the top of the casserole.
  10. Bake covered: Cover the dish tightly with aluminum foil and bake in the preheated oven for 45-50 minutes, or until the sweet potatoes are tender and can be easily pierced with a paring knife without resistance.
  11. Bake uncovered for browning: Remove the foil and continue baking for an additional 15-20 minutes until the top is beautifully golden and slightly crispy.
  12. Rest and serve: Allow the gratin to rest for 10-15 minutes after removing it from the oven. Serve warm to enjoy the creamy texture and rich flavors. For extra browning, you may briefly broil, watching closely to prevent burning if your dish is broiler-safe.

Notes

  • Using a mandoline slicer helps achieve evenly thin sweet potato slices for consistent cooking.
  • Letting the sauce cool before adding cheese prevents clumping and maintains smooth texture.
  • If broiling for extra browning, keep a close eye to avoid burning the cheese topping.
  • This gratin can be prepared a few hours ahead, refrigerated, and baked just before serving.
  • Substitute cheeses if needed: Gruyere or sharp cheddar can complement the flavors well.

Find it online: https://recipeplenty.com/sweet-potato-gratin-with-smoked-gouda-and-rosemary-recipe/