1 teaspoon vegetable oil
1 pound wild American shrimp, peeled, deveined, shells reserved
8 sprigs thyme
4 bay leaves
2 28-ounce cans whole peeled tomatoes with juices
1 pound slab bacon, cut into 1/2" cubes, or thick-cut bacon, sliced into 1/2" strips
4 celery stalks, finely chopped
3 carrots, finely chopped
2 onions, finely chopped
1 leek (white and pale-green parts only), finely chopped
3 garlic cloves, finely chopped
1/2 jalapeño (with seeds), finely chopped
1 pound new potatoes, peeled, cut into 1/2" cubes
Kosher salt, freshly ground pepper
Hot pepper sauce (such as Cholula or Tabasco; optional)
1 pound black or striped bass fillet, cut into 1"–2" pieces
1 pound black or red grouper fillet, cut into 1"–2" pieces
6 slices baguette, toasted
6 cups cooked stone-ground grits or rice
Chopped flat-leaf parsley