Into a large skilled over medium heat, add oil and sweet potato. Toss to coat the sweet potato in oil, cover and cook shaking the pan once half way through for even browning. Cook 3 minutes.
While the sweet poatato is cooking, chop onion and add to the sweet potato after the 3 minutes are up. Toss to distribute, cover and cook for 5-6 minutes longer.
Meanwhile chop the bell pepper and broccoli. After the 5-6 minutes are up, add bell pepper, broccoli, taco seasoning and water to the pan, todd to coat everything in the taco seasoning. Cover and let cook for 3 minutes longer.
Remove from heat, build your tacos and enjoy!