Step 1

Preheat oven to 400 degrees F, and position an oven rack in the middle

Step 2

Place the sweet potato cubes and onion pieces in a large mixing bowl. Add a generous drizzle of extra virgin olive oil (3 to 4 tablespoons) Add salt, pepper, cinnamon and allspice. Toss well to coat.

Step 3

Transfer to a sheet pan. Spread the sweet potatoes and onions well in one single layer (do not crowd the pan.)

Step 4

Roast for 35 to 45 minutes, tossing occasionally, until the sweet potatoes are well cooked through and charred on the edges.