Step 1

Preheat oven to 375 F.

Step 2

Toss cubed sweet potatoes with 2 tablespoons olive oil, salt, and pepper on a large, rimmed baking sheet (lined with parchment paper).

Step 3

Roast the potatoes for 15 or 20 minutes until soft.

Step 4

Proceed with the rest of the recipe while the sweet potatoes are in the oven.

Step 5

In a 10-inch or 12-inch cast iron skillet, cook the sausage, crumbling it, on medium heat on the stovetop for several minutes until it is cooked through. Drain any grease.

Step 6

Add spinach to the skillet with sausage and cook until it wilts.

Step 7

Whisk together the eggs and heavy cream in a large bowl until fluffy. Add shredded Cheddar cheese and stir to combine.

Step 8

Pour the egg and cheddar cheese mixture evenly over the cooked sausage and spinach.

Step 9

Add roasted sweet potatoes, distribute them evenly across the frittata, and sink some of them.

Step 10

Top with shredded pepper jack cheese.

Step 11

Bake for 15 or 20 minutes until the frittata is no longer wobbly in the center.

Step 12

Using oven mittens, transfer the skillet with frittata to a wire rack and let it rest for 15 minutes before serving.