In a hot wok, coat wok with oil and caramelize onions with the ginger. Season. Add sambal and shrimp and stir fry until just cooked through. Deglaze with lime juice and add mangoes. Check for seasoning.
In a mixing bowl, whisk together Dijon, vinegar and oil. Check for seasoning. Toss with snow peas. Place a pile of snow peas in the middle of the plate. Surround with stir fry. Garnish with mango slices.