1. Put turnip/potatoes into largish pot with salted water, and start boiling|
2. Brown off lamb. Drain.
3. Add onions, tomato paste, carrots, flour and stout to lamb ... simmer until thick. Season with salt and pepper.
4. When turnip/potatoes are just soft, drain and mash, using some of the leftover stout to get them creamy.
5. Place lamb mixture into bottom of casserole dish, spoon mash on top. Spread it to the edges with a fork ... don't leave any cracks or you'll get bubbles!
6. Heave the whole thing into a 400F oven for 20 minutes, or until the top browns.... then enjoy with a pint.