Preheat the oven to 400°F (210°C). Pierce each sweet potato 8-10 times with a fork in several locations. Transfer to a baking tray. Roast until tender, about 45-55 minutes.
Add the oil to a large pot on high heat. When hot, add the onions, cooking for 5 minutes. Add splashes of water as needed to de-glaze the pan.
Add the garlic and cook for another 2 minutes, stirring often.
Then add the curry powder, cumin, and coriander. Stir for 30-60 seconds to toast the spices.
Then add the lentils, quinoa, water, bouillon cube, and sambal. Bring to a boil, reduce to a simmer, and cook partially covered for 10 minutes.
Then add the broccoli and bell pepper. Stir, cover fully with the lid, and cook for 5 minutes.
Meanwhile, mix all of the dressing ingredients in a small bowl.
When the cooked sweet potatoes are cool enough to handle, slice them lengthwise and gently squeeze open. Use a fork to mash the inside to make room for the fillings on top.
Scoop the lentil and quinoa mixture into the 'pockets' of the sweet potato. Drizzle the sauce generously over top, and enjoy!
