A simple and comforting bake for all the family allowing you to use up any leftover ham, and using my Chicken Stock.

Ingredients
For the topping
700g sweet potato
25g Gruyere cheese, grated

For the filling
1 large leek
2 cloves garlic, finely minced
Olive oil, for cooking
25g butter
25g flour
200ml milk
200ml Carol's Stock Market Chicken Stock
1 tsp Dijon mustard
350g leftover ham, roughly shredded

Serves
4-6

Method
Preheat the oven to 200°C/180°C fan assisted.

In a large bowl put two layers of muslin or clean tea towel. Peel the sweet potato and coarsely grate into the cloth. Gather the corners of the cloth to close together then squeeze out all of the excess liquid from the sweet potato. Set aside.

To prepare the leek, cut in half lengthways, but keeping the root end uncut, then run the leek under cold water to rinse away any soil. Shake over sink to remove as much water as possible. Cut off hard dark green end and discard. Cut the remaining leek into 4 or 5 pieces.

Heat a large saucepan over medium heat, then drizzle with oil and sauté the leek just until the leek has softened, add the garlic and sauté for another minute. Remove from heat and set aside. Transfer cooked leek to a small dish then return saucepan to medium heat.

Add butter to the saucepan and melt. Once melted, stir in the flour and cook for 1-2 mins.

Remove saucepan from heat then whisk while gradually adding the milk and chicken stock. Return to the heat and increase to medium high. Bring to the boil while stirring constantly to ensure there are no lumps. Do this for 3-4 min until white sauce is thick.

Remove from the heat and whisk in Dijon mustard, then fold in the cooked leek and ham. Taste for seasoning and add salt and pepper if needed.

Spoon the filling into an oven proof dish. Top with grated sweet potato and grated Gruyere cheese then cook in pre-heated oven for 20 minutes or until sweet potato is crispy.