Traditional Irish Guinness Stew - cooking recipe

Ingredients

3 1 pint Guinness stout or 500 ml Guinness stout
1 tablespoon mustard
rosemary (generous amount)
parsley (to taste)
2 bay leaves
3 lbs beef stew meat, cut into cubes
3 tablespoons sunflower oil
4 tablespoons butter
2 large white onions, peeled and sliced
3 stalks celery, chopped
3 carrots, peeled and thickly sliced
1/2 lb white mushroom, quartered
1 tablespoon all-purpose flour
1 garlic clove, crushed
1 beef stock cube
1 pint water or 500 ml water
salt & freshly ground black pepper
sugar

Preparation

In a large glass bowl, combine Guinness, mustard, rosemary, and bay leaves.
Add the beef cubes, stir in, cover, leave to marinate in the fridge overnight.
Preheat oven to 325\u00b0F or 160\u00b0C.
Drain the meat and keep the marinate to one side for later.
On a plate or chopping board, sprinkle the flour and season to your tastes. I recommend just a bit of salt and pepper and a touch of rosemary.
Cover the beef cubes in the flour and set aside.
In a large skillet, melt butter and brown the meat 3-5 minutes each side. Transfer this to a casserole dish and do not clean the skillet (this retains flavours released by the beef).
Add the remaining butter to the skillet, when foamy add the onions and cook until brown and/or tender. Add these to the casserole dish.
Repeat this step for all other vegetables, only adding butter when necessary. Each vegetable should be cooked until tender. This will take a maximum of 5 minutes.
Add the vegetables to the casserole dish followed by the marinate and beef stock.
Cook for 1.5-2 hours or until meat is tender. Stir occasionally. The Guinness will reduce a lot, but if it looks too dehydrated you can add more.
Taste occasionally, and if it is too sharp you can add sugar to cut the taste.