Sprinkle berbere over fish and leave for 1 hour to marinate.
Heat enough oil in a large skillet for deep frying. Add fish pieces and fry until golden on all sides and cooked through. Remove to a paper towel lined plate to absorb excess oil. Sprinkle with a little salt.
Add onions and cook until golden and caramelized, about 10 minutes. Most of the oil will have evaporated. Add garlic and chiles. Cook for 1 more minute.
Return fish to the pan. Add lime juice and toss to combine.
Serve with lime and an extra garnish of more berbere.