1. In a bowl, mix the orange juice, vinegar, soy sauce, sugar and cornstarch.
2. In a wok or large frypan, heat the oil over high heat until smoking.
3. Add the chiles and salt; stir-fry until browned, 45 seconds.
4. Add the onion, ginger and garlic; stir-fry until fragrant, 15 seconds.
5. Add the peppers and cook until crisp-tender, 30 seconds.
6. Add the shrimp and stir-fry until nearly cooked through, about 5 minutes.
7. Stir the sauce, add to the wok and cook until thickened slightly, 30 seconds.
8. Stir in the cashews and sesame oil; serve.