Pre-heat the oven to 300ºF.
In a Dutch oven, heat a drizzle of oil over medium-high heat. Add the sausage; brown and remove to a plate.
Reduce the heat a bit and add 1/4 cup oil and about 4 tablespoons flour to the pot. Stir for 10-12 minutes until golden and fragrant. Add the chopped vegetables, chili pepper, garlic, bay, dried spices, herb bundle, salt and pepper and stir for 7-8 minutes to soften. Add the stock and a couple of tablespoons of hot sauce; simmer to thicken. Add the cooked chicken and sausage back to the pot.
Warm the chips in the oven on baking sheets.
Heat a skillet over high heat with a thin layer of vegetable oil. Season the shrimp with seafood seasoning and cook in the hot pan, 2-3 minutes, to cook through.
Fill bowls with a layer of sweet potato and tortilla chips. Sprinkle with the cheese (optional) and top with gumbo sauce and a few shrimp; garnish with scallions.