Why It WorksAllowing for a choice between meats means home cooks can have this classic any way they like it; the recipe works no matter what.Rinsing the potatoes before and after cooking removes surface starch, ensuring that the mash doesn't end up gummy.Nontraditional ingredients, like red wine, tomato paste, and Parmesan cheese, add depth and complexity.Worcestershire and optional Marmite are classic British umami bombs, adding savory depth to the meat.Years ago, while studying in London, I noticed a critical detail in the way a lot of Brits eat that helps explain why their food often gets a bad rap from outsiders. Let's say, just as an example, that I'm at a pub eating dinner, and on my plate are some mashed potatoes, boiled peas, and roast meat with its pan drippings. If I were to attack that plate the way I'm most inclined to, I'd scoop up some peas and chew them up, and think something like,sweet but bland. Then I'd hit the mashed potatoes, and I'd remind myself thatbuttery Frenc...