5 ½poundssweet potatoessuch as garnet or jewel, scrubbed (often labeled yams)
½cup1 stick unsalted butter, ghee, or vegan butter, divided + additional for greasing baking dish
¼cupfresh rosemary leavessave the stems for the turkey cavity
¼cupfresh sage leaves
1 ½cupscoarse FRESH sourdough breadcrumbspulse fresh, preferably stale, bread in a food processor (or use panko
2large shallotschopped or ½ onion, finely chopped
1cupany kind of unsweetenedplain milk (dairy or non-dairy)
3large eggs
1 1/3cupsfinely grated Parmesan or Pecorino cheese
Sea salt and freshly ground black pepper to taste
Instructions
Preheat oven to 400 degrees. Place the sweet potatoes on a parchment-lined baking sheet and bake in the oven until tender, about an hour, but could be more depending on size. You can also boil peeled, cubed sweet potatoes in water for 15 minutes or until tender and drain.
Lower the oven temperature to 375 degrees. Butter a 13 x 9 inch baking dish.
In a small saucepan over medium heat, melt 6 Tablespoons of butter with the rosemary and sage and cook, stirring occasionally, until the butter foams and then browns, about 5 minutes. You are making browned butter. If using vegan butter, just cook the herbs until crisp and don’t try to brown the vegan butter. Set aside to cool slightly.
When the sweet potatoes are cool enough to handle, peel and discard the skin and place potatoes in a large bowl. Spoon half of the browned butter-herb mixture onto the sweet potatoes.
Place the breadcrumbs in a small bowl and pour remaining browned butter-herb mixture on top and toss to coat.
In the same saucepan, melt 2 Tablespoons butter over medium heat. Add the shallots and cook, stirring often, until tender and translucent, about 5 minutes.
In the bowl of a food processor fitted with a metal blade, add half the sweet potatoes, butter and herbs, plus half the shallots, half the milk, 1 or 2 of the eggs and half the Parmesan. Just eyeball measurements since everything will get pureed and mixed together. Puree until smooth. Season with salt and pepper to taste. Pour into the prepared baking dish. Puree the remaining ingredients and stir into the pureed sweet potato in the casserole dish. Can be made up to this point one day in advance and kept covered in the refrigerator. Top with bread crumb mixture and bake until crumbs are golden and crisp, about 20-25 minutes.
Notes
You can bake this up to 4 hours in advance and serve it warm or at room temperature. If you omit the cheese, you will need to add a bit more salt.