2 sweet potatoes, sliced into 1/8-inch thick coins
1 onion, quartered then cut into 1/2-inch slices
2 Tbsp. vegetable or canola oil
1/2 tsp. sea salt (or more or less to taste)
lots of freshly ground black pepper
optional: additional seasonings
Preheat oven to 400 degrees.
Prepare a baking sheet with aluminum foil or parchment paper, and spray with cooking spray. Transfer vegetables to the baking sheet, and spread so that they are evenly spaced in a single layer.
Bake for 20-30 minutes, or until onions begin to crisp and brown, and sweet potatoes are cooked through.