For a brilliant (and slightly healthier) take on crema, Phoebe Lapine blends avocado with the sour cream. Slideshow: Best Taco Spots in the U.S.
Preheat the oven to 400°. In a 9-by-13-inch glass or ceramic baking dish, mix the shallot with the garlic, lime juice, honey, hot sauce, olive oil and 1 teaspoon of salt. Arrange the fish in the dish and turn several times to coat. Let the fish stand in the marinade for 10 minutes.
Roast the fish for 10 minutes, until cooked through, then flake with a fork.
Meanwhile, in a small food processor combine the sour cream with the avocado, cilantro, garlic, water and 1 teaspoon salt. Puree until smooth.
Wrap the tortillas in foil and warm in the oven for 1 minute, until soft and pliable. Arrange the fish in the tortillas and top with the avocado crema and diced mango. Garnish with cilantro leaves, fold the tortillas over the filling and serve right away.