Vegetarian Enchiladas Suizas

Name: Vegetarian Enchiladas Suizas
Ingredients: 2 tablespoons vegetable oil; 1 large poblano, ribs and seeds removed, thinly sliced (1 ½ cups); 1 small red onion, halved and thinly sliced (1 ¼ cups); Kosher salt and freshly ground pepper; 1 medium zucchini, cut into a ½-inch dice (1 ½ cups); 1 ½ cups green salsa (from a 16.7-ounce jar), such as La Costeña; 6 corn tortillas (each 6 inches); 5 ounces low-moisture mozzarella, cut into a ½-inch dice; ⅓ cup Mexican crema or sour cream; Shredded iceberg lettuce, sliced radishes, and halved cherry tomatoes, for serving