In a small bowl, whisk together the peanut butter, lime juice, maple syrup, liquid aminos, sesame oil, garlic and sriracha. Set aside.
Heat the oil in a large pan over medium-high heat. Once the oil is warm, add in the onion and cook until translucent, about 7-10 minutes.
Add in the broccoli and cook for another 5 minutes or until the broccoli is crisp tender. Add in the sweet potato noodles and cook, tossing frequently, until the noodles are still slightly crisp, about 5 minutes.
Turn down the heat to low and add in the peanut sauce. Toss the sauce with the noodles to coat. Cook until warmed through, about another 2 minutes. Serve with desired toppings.