Savory Sweet Potato Casserole in the dish and on a plate

Savory Sweet Potato Casserole

A rich holiday-worthy casserole featuring herbed brown butter and aged cheese that perfectly complement the earthy sweetness of the sweet potato. Serve as a substitute (or in addition to!) traditional mashed potatoes.
Course Side Dish
Cuisine American
Keyword casserole, sweet potatoes
Prep Time 30 minutes
Cook Time 1 hour 10 minutes
Total Time 1 hour 40 minutes
Servings 20 servings
Calories 315kcal
Author Karen Gibson


  • 4 pounds sweet potatoes, scrubbed clean
  • 8 tablespoons butter
  • 1/2 ounce sage leaves or 20 leaves*, sliced chiffonade
  • 2 tablespoons chopped fresh rosemary leaves
  • 1 1/4 cups Panko breadcrumbs
  • 1 large shallot, diced
  • 1 cup heavy cream
  • 2 eggs, beaten
  • 1 cup grated Parm or other flavorful aged cheese
  • kosher salt and pepper
  • finely grated zest from one lemon


Prepare the sweet potatoes (2 options)

  • Instant Pot: add 1 cup of water to a 6 or 8 quart unit (3 quart is too small). Stack the sweet potatoes in the unit. Secure the lid, and set the valve to Seal. Set manual pressure to high, at 14 minutes. After the unit finishes cooking, allow to natural release for 10 minutes, then quick release the remaining pressure. Open the lid carefully, taking care to mind drips from the lid. The potatoes should be soft, and probably are possibly split open.
  • Oven: Preheat oven to 350 degrees F. Line two baking sheets with foil. Slice the potatoes in half lengthwise and arrange them cut side down on on the sheets. Roast them for 60 to 75 minutes, or until the potatoes are soft and squeezable. Let cool on baking sheets until handleable.

Continue with the other components

  • While the potatoes are cooking (either method), heat 6 tablespoons of the butter in a small saucepan over medium. Add the herbs and stir well. Cook until the butter foams and then browns. The sage should be a little crispy. Remove from heat.
  • Preheat oven (or raise existing heat) to 400 degrees F.
  • Scoop out the flesh from the skins (discard the skins) and add to a large mixing bowl. Mash with a potato masher (doesn't need to be smooth at this point, just begin to come together). Stir about half of herbed brown butter into the potatoes.
  • Add the breadcrumbs to the remaining butter in the saucepan and stir to coat. Transfer to a bowl and set aside.
  • Add the remaining 2 tablespoons of butter to the same saucepan and place over medium heat. Stir in the shallots and cook until golden. Pour in the heavy cream, increase heat and bring to a simmer. Remove from heat, and use an immersion blender to smooth out the cream.
  • Add the eggs, cheese, and cream to the potatoes, and use the immersion blender to blend the potatoes until smooth.
  • Spoon the potato mixture into a 2 quart baking dish (shallow and long is preferred over tall and square). If you want to get fancy, create swirls in the mixture with a spatula. Top with the herbed breadcrumbs.
  • Bake for 20 to 25 minutes, or until the breadcrumbs are golden brown. Sprinkle the lemon zest over the top, and serve.


* 1/2 ounce is the typical size of sage found in clam shells at the grocery. Pluck the leaves off the stems.
Make ahead: Can be made one day ahead of time. Prepare all parts of the recipe. Fill the 2 quart baking dish with the potatoes and cover. Store the breadcrumbs in a separate container. Refrigerate everything. Allow to come to room temperature before covering the potatoes with the breadcrumbs and baking. 
Inspired by Bon Appetit


Serving: 1serving | Calories: 315kcal