|3T||Vinegar (preferably cider vinegar)|
|(1T = one tablespoon = 15ml)|
Slice the onion into slices about 5mm thick and fry in the oil for 5 minutes on a medium heat.
Slice the bacon rashers cross-wise into pieces about 1cm wide. Add to the pan and fry for another 3 minutes.
Slice the beef into pieces about the same size as the bacon. Fry for another 3 minutes or so. (The onion should be slightly browned and the bacon and beef should have a cooked-colour.)
Add the black treacle, vinegar and guiness. Bring to a boil then turn the heat right down so that the sauce is just simmering. You want the sauce to slowly boil down and thicken. This should take about 30 minutes.
And also ...
You might also enjoy reading Functional and dynamic programming in the design of parallel prefix networks by Mary Sheeran (Journal of Functional Programming 21(1), 2010, pp59-114).