In a large wok or skillet over medium-high heat, saute the sliced onion in 2 tablespoons of peanut oil until translucent; about 3 minutes.
Add garlic and sliced bell pepper and saute about 4 more minutes; until the red pepper begins to soften.
Add spiralized sweet potato noodles and cook for 2-3 minutes, gently folding up from the bottom of the pan a few times. Add 1/4 cup water to the pan and cover immediately. Steam for 2 minutes. Check for doneness, and then cover again and cook 2 more minutes. Repeat until noodles are tender but not mushy. (You are not making mashed potatoes!)
Add remaining sauce, cooked shrimp, and chopped cilantro and toss gently to combine.