1) Preheat oven to 220C/Gas 8.
2) In a deep skillet or a Dutch oven heat 2 tablespoons oil over high heat. Add meat and break up with a wooden spoon, season with salt and pepper and poultry seasoning.
3) Place sweet potatoes in a pot, cover with water, cover pot, bring to a boil, add salt and cook 15 minutes until tender.
4) Add onions, carrots and celery into the turkey. Stir, and cook for 5 minutes. While vegetables are cooking, heat 2 tablespoons butter in a small pot over medium heat. Add flour to melted butter and whisk 1 minute. Whisk in stock and season with salt, pepper and Worcestershire. Cook a few minutes to thicken.
Stir peas into meat and turn heat off.
5) Drain potatoes and return pot to heat. Add remaining 2 tablespoons of butter and melt over medium heat. Peel and slice banana and add potatoes to the pot. Season the potatoes with salt and pepper and a few dashes hot sauce. Mash potatoes and banana to combine, adjust seasoning. Top the meat with the potatoes. Cover potatoes with cheese and place in the oven to melt cheese, about 5 minutes.