Chicken & white bean stew

This flavorsome, low-fat casserole freezes really well, so why not make double and freeze half for next time.   Ingredients (4 servings): 2 tbsp olive oil 400g boneless, skinless chicken thighs, trimmed and cut into chunks 1 onion, finely chopped 3 carrots, finely chopped 3 celery sticks, finely chopped 2 thyme sprigs or ½ tsp dried…