Slow cooker chicken casserole

Ingredients:

knob of butter

½ tbsp rapeseed or olive oil

1 large onion, finely chopped

1 ½ tbsp flour

650g boneless, skinless chicken thigh fillets

3 garlic cloves, crushed

400g baby new potatoes, halved

2 sticks celery, diced

2 carrots, diced

250g mushrooms, quartered

15g dried porcini mushroom, soaked in 50ml boiling water

500ml stock made with 2 very low salt chicken stock cubes (we used Kallo)

2 tsp Dijon mustard, plus extra to serve

2 bay leaves

Method:

Heat a knob of butter and ½ tbsp rapeseed or olive oil in a large frying pan, cook 1 finely chopped large onion for 8-10 mins until softened and starting to caramelise.
Meanwhile, put 1 ½ tbsp flour and a little salt and pepper in a bowl and toss 650g boneless, skinless chicken thigh fillets in it.
Add 3 crushed garlic cloves and the chicken to the pan and cook for 4-5 mins more until the chicken is starting to brown.
Transfer to your slow cooker, along with 400g halved baby new potatoes, 2 diced celery sticks, 2 diced carrots, 250g quartered mushrooms, 15g dried and soaked porcini mushrooms with the 50ml soaking liquid, 500ml chicken stock, 2 tsp Dijon mustard and 2 bay leaves.
Give it a good stir. Cook on Low for 7 hours or High for 4 hours.
Remove the bay leaves and serve with a little Dijon mustard on the side.