Preheat the broiler.
Heat the oil in a medium non-stick skillet. Sauté the scallions, jalapeno and garlic. Add cayenne and paprika over medium heat until soft, approximately 2 minutes. Remove and place in a mixing bowl.
Add the crab meat, mayonnaise, crème fraiche, lemon juice and ½ teaspoon salt to the vegetable mixture. Fold until mixed together, trying not to break the crab meat apart too much.
Transfer the crab dip to a medium (8 x 8 or comparable) casserole dish.
Take your tortilla chips and put them in a food processor and pulse until they are the texture of breadcrumbs.
Sprinkle the tortilla chips over the top of the dip. Bake under the broiler until golden brown on top and heated through, 2 minutes.
Serve immediately with tortilla chips on the side for dipping.