Roasted sweet potatoes in a sweet and sour chili sauce

This is a take on manchurian potatoes that you get in an Indo Chinese restaurant. Typically this dish is made with regular potatoes - russet potatoes work well, but I decided to use the white Japanese sweet potatoes. The sweetness of the potatoes is a nice contrast to the spiciness of the sauce. The spring onions added at the end give a pop of color and freshness to the dish. If I had cilantro on hand, I would have added some finely chopped cilantro leaves as well.

Roasted sweet potatoes in a sweet and sour chili sauce

1 lb white sweet potatoes or Japanese sweet potatoes (they have a pink skin)
1 bunch scallions, thinly sliced - whites and greens separated
1 tablespoon minced garlic
1 tablespoon light soy sauce
1 teaspoon dark soy sauce
2 teaspoons tomato ketchup
1 teaspoon toasted sesame oil
1 tablespoon Chinese rice wine
1 teaspoon Chinese black vinegar or balsamic vinegar
1/2 - 1/3 teaspoon dried red chili flakes (depends on how hot you like it)
1/4 teaspoon kosher salt
2 tablespoons canola or peanut oil

1. Preheat the oven to 450 F.
2. Peel the potatoes and cut them into batons 1/2 inch x 11/2 inch long. Toss them in some canola or peanut oil and a sprinkling of salt.Spread them in a single layer on a baking sheet and bake in the center rack for 15 minutes till they are golden on the edges.
3. In the meantime, in a small bowl, mix the soy sauce(s), ketchup, sesame oil, rice wine, vinegar, and chili flakes and stir to combine. Set aside.
4. When the sweet potatoes are roasted, heat a 10 inch saute pan over medium heat. Add 1 tablespoon canola oil and the minced garlic. When the garlic begin to sizzle, add the whites of the onions and saute for 30 seconds. Add the sauce and potatoes and mix well. Once the potatoes are well coated with the sauce and warmed through, sprinkle the sliced scallion greens and remove to a serving dish.

Serves 3 to 4 as part of a multi-course meal