Heat a large wok with 1 tbsp oil over medium high heat.
Pat shrimp dry and toss the shrimp in the arrowroot powder till well coated.
Working quickly, add the shrimp to the wok one at a time so they don't stick together. Make sure not to over crowd the pan (you may need to do this in two batches).
Cook for 2-3 mins till the shrimp just start to turn pink. Careful not to over cook them.
Remove the shrimp from the pan, add the remaining 2 tbsp of oil to heat up.
Add the onion and garlic and dried red chilies. Cook for 1 min till it starts to get fragrant.
Add the peppers and diced chillies. Cook for 2- 3 mins, add the shrimp back in.
Add the coconut aminos and toss to coat. Cook for 1 more min till shrimp are cooked through.
Serve warm over zucchini noodles or rice.