Preheat oven to 425 degrees.
Coat prepared Brussels sprouts with a light and even layer of olive oil and spread evenly onto a baking sheet.
Sprinkle lightly with salt and pepper.
Roast in oven for 20-25 minutes, turning about halfway through.
Add pecans onto baking sheet in the last five minutes of roasting.
Continue roasting until pecans are lightly toasted and Brussels sprouts are golden brown.
In a small saucepan, saute garlic, ginger, and green onions in a tablespoon of olive oil until lightly browned.
Add chile paste, dried chiles, soy sauce, vinegar, sugar, and water to the saucepan and bring to a simmer.
Add cornstarch mixture and stir continuously, cooking 1-2 minutes longer until sauce thickens.
Pour prepared sauce over the roasted Brussels sprouts and pecans; toss to coat evenly.
Garnish with a few green onion slices and serve immediately.