Ingredients:

  • 4 large Sweet Potatoes (approx. 1.4 kg), scrubbed, unpeeled
  • 4 Tbsp Unsalted Butter, divided
  • 2 large Shallots, finely diced
  • 3 cloves Garlic, minced
  • 1/2 cup Heavy Cream (Double Cream)
  • 1/2 cup Chicken or Vegetable Stock, low-sodium
  • 1 Tbsp Fresh Sage, finely chopped
  • 1 tsp Salt (Kosher/Sea)
  • 1/2 tsp Black Pepper, freshly ground
  • Pinch Freshly grated Nutmeg
  • 1/2 cup All-Purpose Flour
  • 1/4 cup Pecans or Walnuts, roughly chopped
  • 1/2 cup Parmesan Cheese, freshly grated
  • 1 tsp Fresh Thyme Leaves
  • 4 Tbsp Unsalted Butter, very cold, cut into 1/2-inch cubes
  • 1/4 tsp Salt

Instructions:

  1. Preheat the oven to 400°F (200°C). Pierce the sweet potatoes several times with a fork. Place potatoes on a parchment-lined baking sheet and roast for 35–45 minutes, or until the flesh is very tender. Allow potatoes to cool slightly (about 10 minutes), then slice lengthwise and scoop the flesh into a large mixing bowl, discarding the skins.
  2. Prepare the aromatics: Melt 2 Tbsp of butter in a small skillet over medium heat. Add the diced shallots and cook until softened and translucent (about 5 minutes). Add the minced garlic and chopped fresh sage, cooking for 1 minute until fragrant. Do not brown the garlic.
  3. Create the base: Add the remaining 2 Tbsp of butter, heavy cream, stock, salt, pepper, and nutmeg to the sweet potato flesh. Use a potato masher or fork to mash the mixture until mostly smooth, leaving a little texture for body.
  4. Combine and Season: Fold in the sautéed shallot-garlic mixture. Taste the potato base and adjust seasoning as needed. Spoon the mixture evenly into a 9x13-inch baking dish.
  5. Prepare the Streusel: In a medium bowl, whisk together the flour, chopped nuts, grated Parmesan, thyme leaves, and salt. Add the very cold, cubed butter. Use your fingertips or a pastry blender to cut the butter into the flour mixture until it resembles coarse crumbs or rough peas.
  6. Assemble and Bake (Covered): Sprinkle the streusel topping evenly over the sweet potato base. Place the casserole dish in the preheated 400°F (200°C) oven and bake, covered loosely with foil, for 25–30 minutes to heat through.
  7. Bake (Uncovered): Remove the foil and continue baking for 10–12 minutes, or until the streusel is golden brown, crisp, and bubbling slightly around the edges.
  8. Rest and Serve: Let the casserole rest for 10 minutes before serving. This allows the creamy base to set up properly.