Mix the flour with the spices. Dredge the trout and deep fry at 375 degrees until golden brown. Season with salt. Repeat process with the onions. On an oval plate, place a small mound of the long beans and top with trout. Encircle with sauce. Garnish with crispy onions.
In a saute pan coated with oil, cook lemon grass and shallots. Deglaze with fish sauce. Add pineapple, mango and lime juice. Check for seasoning.
Deep fry long beans until they are wrinkled. Transfer to a stainless bowl and toss with sambal and sesame oil. Check for seasoning.