I recently had the experience of helping out to cook a dinner serving 22+ diners for a charity shelter. The dish I chose to do with the volunteers was Gordon Ramsay’s Shepherds Pie. The difficult step in making this dish was turning 15 lbs of yukon gold potatoes into a mashed potato topping. For years I’d been peeling potatoes, then boiling them and then mashing them. In this case, peeling so many potatoes and also getting the potato eyes out would take so much time as to be prohibitive – even for a small group of people.
Serendipitously, I came across an article on the web from Americas’ Test Kitchen/Cooks Illustrated that mentioned NOT peeling the potatoes in order to make better quality mashed potatoes (see https://www.cooksillustrated.com/articles/61-how-to-improve-mashed-potatoes-with-3-handy-tips). In essence, the technique was to simply boil the unpeeled potatoes in salted water UNPEELED, then cut the cooked potato in half where the potato circular cross section would be exposed. One would then load the cut potatoes, cut side facing the output holes of the potato ricer and then press. Out would come the potato flesh WITHOUT the skin. One would then
remove the peel left in the ricer. At that point, one would repeat the processing of loading a cut potato, ricing and then removing the residual peel until all the potatoes were processed. So the ‘peeling’ issue would be much easier at the potato ricing stage of the process. And the amount of time processing the potatoes was greatly reduced. It should be of note that Chef Robuchon had specified cooking UNPEELED potatoes for his potato puree (The Complete Robuchon, p. 623), draining the cooked potatoes AND THEN peeling them and putting them into a potato ricer.
A couple of other observations: In Chef Robuchon’s book just referenced, it should be noted that the recipe specifies a potato:butter ratio of 4:1. HOWEVER – Chef Steve Benjaminof L’Atelier de Joël Robuchon@Las Vegas MGM Grand reports that Chef Robuchon’s restaurants use a potato:butter ratio of 2:1 (see: https://www.greenmarketrecipes.com/vegetables/robuchons_mashed_pototoes.htm). And while Chef Robuchon’s recipe makes an order for 6 servings, my wife and I have had the experience that we can only split an order made from 1 lb of potatoes (at most).
The Las Vegas MGM Grand Robuchon ingredient list is:
1 lb Ratte potatoes (or fingerlings or Yukon golds)
250 grams (1/2 lb==2 sticks of butter) chilled unsalted high quality French butter– chilled and cut into small pieces
Hot Milk, as needed 1/2 -3/4 cup
salt to taste
Essentially, I would make the mash by boiling the potatoes in salted water for about 30 minutes and then rice the potatoes as described above. I would then add the butter bit by bit making sure it was well incorporated. Once the butter was gone, I’d add the milk that was brought to a boil and then add it bit by bit until it too was well incorporated and then season. The Complete Robuchon specifies salt/pepper to taste. When I attempt to make this for Thanksgiving dinner, I will have to determine the amount of 4:1 salt/pepper to season his potato puree. Chef Robochon indicates that he further processes the mash through a fine sieve/tami to make the puree finer and lighter.
One other note, I recently made Chef Robuchon’s mashed potatoes with olive oil (The Complete Robuchon, p. 623-624) which blended 2 lbs of riced potatoes with 2 cups of olive oil. That seemed a bit excessive. As it turned out, my wife and I determined that 1/4 c of olive oil with 1 lb of potatoes was almost too much. Additionally, I would strongly recommend a very high quality extra virgin olive oil since it would make its flavor profile known in this particular mashed potatoes.