2 pounds garnet sweet potatoes, peeled and sliced 1/4-inch thick
2 tablespoons olive oil
1 red onion, halved and sliced thin
1 tablespoon Dijon mustard
1/4 cup red wine vinegar
1 tablespoon maple syrup
1 Golden Delicious apple, diced
-- Kosher salt and ground black pepper, to taste
2 tablespoons chopped chives

Instructions: Place sweet potato slices in a pot and cover with cold, lightly 
salted water. Bring slowly to a boil, and let simmer until potatoes are 
tender but still hold their shape, about 10-15 minutes. Drain carefully 
and set aside.

Meanwhile, heat oil in a frying pan on medium heat. Add half of the onions, 
and saute until caramelized, about 10 minutes. Add the mustard, red wine 
vinegar and syrup, and stir until incorporated. Let simmer for about 2 minutes.

Add the apples, stir to combine, and remove from heat. Mix gently with the 
cooked sweet potatoes and remaining onions, and season to taste with salt 
and pepper. Sprinkle chives on top, and toss to combine.

Note: This recipe can be easily doubled.

Source: San Francisco Chronicle