Chipotle Shrimp Tostadas

Name: Chipotle Shrimp Tostadas
Ingredients: 1 teaspoon vegetable oil, plus more for frying; 4 corn tortillas; Kosher salt; 24 large shelled and deveined shrimp (about 1 pound); 1 teaspoon chipotle chile powder; 4 cups shredded cabbage or coleslaw mix; 1 medium tomato, seeded and cut into 1/4-inch dice; 2 scallions, thinly sliced; 1/4 cup sour cream; 1 1/2 teaspoons fresh lime juice; 1 Hass avocado, thinly sliced; 2 medium radishes, thinly sliced; 1/4 cup cilantro leaves; Lime wedges, for serving