To prepare the fish and sweet potato chips in the air fryer, you'll need: 1 pound frozen fish, 2 tbsp. kosher salt, 1/2 cup each melted butter and olive oil, and 1 cup sweet potatoes. In a large skillet, heat the oil over medium-high heat. Add the potatoes and cook, stirring frequently, until they are lightly browned, about 5 minutes. Remove from the heat and set aside to cool.