Sounds very much like my Bob-standard beef casserole, the only differences being:
1) Liquid is half a pint or so of beer. Any sort, from pale ale to Guinness, will do.
2) Start off in a slow oven (300°F, 160°C, gas #2), and wind the temperature down as needed to keep the pot just on the point of boiling.

I opine that since water boils at 100°C and isn't going to get any hotter, any additional heat will just be wasted. The only exceptions are pasta, where the movement is needed to keep it from sticking, and of course if you're reducing stuff. I invite discussion.