Whisk the mayonnaise, chipotle, lime juice, and 1/4 tsp. salt in a small bowl.
Put the cabbage, onion, radishes, and cilantro in a medium bowl and stir in 1/4 cup of the sauce. Set the remaining sauce and the slaw aside.
Stir together 4-1/2 oz. (1 cup) of the flour, the beer, and 1 tsp. salt in another medium bowl. Let stand 15 minutes.
Toss the fish with 1/2 tsp. salt in a medium bowl. Put the remaining 2-1/4 oz. (1/2 cup) flour in a shallow bowl.
Pour the oil into an 8-inch-wide, 4-quart pot to a depth of 2 inches. Clip a deep-fry thermometer to the pot, and heat over medium heat to 375°F.
Meanwhile, heat a griddle or heavy-duty 12-inch skillet over medium heat until hot. Working in batches, heat the tortillas in a single layer, turning once, until soft with light brown spots. Stack in a cloth-lined basket or plate and wrap to keep warm.
Working with a few pieces at a time, dredge the fish in the flour, shaking off the excess. Coat the fish in the batter and add to the oil. Fry, turning as necessary, until golden and just cooked through, 3 to 4 minutes. Transfer to a paper-towel-lined plate to drain. Repeat with the remaining fish, adjusting the heat as necessary to maintain the oil temperature.
Put a piece of fish in each tortilla, and top with some of the slaw and a drizzle of the sauce. Serve with the lime wedges.
nutrition information (per serving):
41, Fat Calories
360, Saturated Fat
20, Monounsaturated Fat
46, Polyunsaturated Fat
Photo: Scott Phillips