How to make the best Irish bacon, cabbage and parsley sauce for St Patrick's Day

Darina Allen's bacon and cabbage with parsley sauce is hard to beat.
For many of us, bacon and cabbage is our national dish making it the perfect dinner for St Patrick's Day. The original Irish one-pot meal, Darina Allen says that it was down to necessity rather than ease.
"Traditionally, the cabbage was always cooked in the bacon water. People could only hang one pot over the fire at a time, so when the bacon was almost cooked, they added the cabbage for the last half hour or 45 minutes of cooking.