4 mirlitons (chayote squash), halved (about 3 pounds)
1 stick (8 tablespoons) unsalted butter
2 teaspoons Cajun seasoning
1 stalk celery, chopped
1 clove garlic, minced
1/2 green bell pepper, chopped
1/2 small onion, chopped
Kosher salt and freshly ground black pepper
4 ounces andouille sausage, chopped
1 teaspoon hot sauce, plus more for serving
1 plum tomato, chopped
4 ounces jumbo lump crabmeat, picked through
4 ounces peeled and deveined medium shrimp, tails removed, chopped into 1/2-inch pieces
1/2 cup panko breadcrumbs
1/4 cup chopped fresh parsley