Preheat the oven to 400°F and grease a 9-by-13-inch baking dish.
Arrange the taco shells in the baking dish (try to fit as many as you can). Divide the shredded chicken between the taco shells, then scatter the corn and black beans over the top. Sprinkle the shredded cheese over the tacos (add to your liking).
Bake the tacos until the cheese is melted and the edges of the shells are beginning to brown, about 15 minutes. Let cool slightly.
Drizzle the Mexican crema over the tacos and garnish with diced avocado, shredded romaine lettuce, sliced chile, julienned radish, and cilantro. Serve right away, passing hot sauce and lime wedges at the table.