In bowl put crabmeat, onions, scallions, pepper and jicama. Toss to combine. In another bowl, whisk together curry oil, mayonnaise, and creme fraiche. Add curry mixture to crab mixture, season with salt and black pepper.
In skillet heat oil and curry powder slowly, stirring constantly until curry is fragrant without burning. Remove from heat and set aside to cool. Let curry settle overnight then pour off oil. Store in refrigerator.