Slow cooker chicken casserole recipe | Good Food

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
• 2 tsp Dijon mustard plus extra to serve
• 2 bay leaves