Moqueca Brazilian Fish Stew

Name: Moqueca (Brazilian Fish Stew)
Ingredients: 1 1⁄2 lb. boneless, skinless catfish filets, cut into 2″ pieces; 8 oz. medium shrimp, peeled and deveined; 1⁄4 cup fresh lime juice; 8 cloves garlic, minced; Kosher salt and freshly ground black pepper, to taste; 3 tbsp. olive oil; 1 1⁄2 small yellow onions (1 minced, 1/2 thinly sliced); 1 Italian frying pepper, stemmed, seeded (half minced, half thinly sliced); 2 plum tomatoes, cored (1 minced, 1 thinly sliced); 1 cup fish or vegetable stock; 1 cup coconut milk; 2 tbsp. palm oil (available at My Natural Market); 1⁄4 cup minced cilantro; 1⁄2 cup minced Thai basil leaves; Cooked white rice, to serve