Preheat the oven to 350 degrees F (175 degrees C). Coat the bottom of a glass or nonstick baking dish with olive oil, just enough to coat.
Place sweet potatoes in the baking dish and turn them so that they are coated with the olive oil. Sprinkle moderately with salt and pepper.
Bake in the preheated oven until soft, about 60 minutes.
Heat grapeseed oil in wok over medium heat. Add kale and collard greens and cook until wilted, stirring frequently, about 10 minutes. Add onion, peppers, carrots, garlic, and ginger. Stir-fry for about 5 minutes. Mix in sweet potatoes and mushrooms, and cook for 5 minutes.
Remove from heat, stir in Thai peanut sauce, and serve.