Heat the oil in a saucepan. Add the onion, chili peppers, and garlic and gently roast for about 5 min, stirring occasionally, until softened.
Add cilantro, crab tails, tomatoes and lime juice and gently roast ingredients for another 3-4 min until crab tails turn pink, stirring occasionally. Season to taste with salt and freshly ground pepper and serve hot or chilled.