About halfway through making Richard Olney's Potato and Leek Soup, the question suggests itself, "OK, what exactly is going on here?"

The confusion arises not from what you might expect in a French cookbook — complexity, unfamiliar terms, technical difficulty — but from the recipe's merciless spareness and simplicity.

Five ingredients: Water, salt, potatoes, leeks, butter.

Instructions? Boil the sliced vegetables in the salted water and stir in the butter just before serving. No sautéing. No stock. No cream. No wine. No herbs.

Which prompts the question, as you lean into the sharply fragrant steam above the soup pot, and poke at an agitated mat of simmering leek slivers, "Am I actually making soup? Or am I just boiling some vegetables?"

The recipe straddles two pages of Olney's classic cookbook, "Simple French Food" (Houghton Mifflin Harcourt, 454 pages, $24.99), just reissued in a 40th-anniversary edition. It was his second book, after "The French Menu Cookbook," which the Observer Food Monthly recently judged the best cookbook ever.

If you're asking yourself, "Richard who?" you're not alone among Americans. Although he mingled with the most famous Anglophone chefs and food writers of the 20th century — James Beard, Julia Child, M.F.K. Fischer, Elizabeth David, Alice Waters — he built his fearsome but slightly cultish reputation on a life spent in retreat: cooking, painting, writing, foraging and hosting the occasional legendary feast — on a rocky Provençal hillside, in a small house with a big kitchen, up a road he laid himself, in the village of Solliès-Toucas, surrounded by the vines of Bandol.

This slightly monkish quality forms a great part of his appeal. He was not only advocating for simple, seasonal, local food back when Alice Waters was still in her 20s, but he actually carved for himself a simple, focused personal world out of the distractions and complexities of modern life — something we all say we want to do, just before we reach for our iPhones to check our Instagram feeds.

Life beyond recipes

It is clear throughout "Simple French Food" that, however exhaustively informed and precise, this is not a cookbook in the traditional sense of handing down a set of recipes to be followed. Yes, it is divided into familiar chapters, like "Salads," "Fish" and "Vegetables," but this is really a book about the good life, accessed in part through food. A book about the pleasures of eating as a prerequisite to one of Olney's favorite words: well-being.

On the other hand, it shouldn't be confused for the garrulous ramblings of a wise old uncle. Let Olney walk you through the boning of a rabbit, the poaching of an egg or the producing of homemade vinegar, and you will know you are in the hands of not just an epicurean and enthusiast, but also a technician, who has clearly spent thousands of loving hours standing at that handmade Provençal hearth, stirring his legendary oxtail pot-au-feu, perfecting his "impromptu" composed salad (which he takes six pages to describe), or breaking heads of garlic into cloves for his Chicken With 40 Cloves of Garlic.

I like to imagine him there, finding everything delicious, but some things just a little more delicious than others, and then wondering why.

A practical matter

I am standing over his Potato and Leek Soup at 6 p.m. on a school night, and the first snowfall of the year looks in every way unlike Provence. I am here, not in search of the good life, but because a CSA delivery has stuffed our pantry with potatoes and leeks, and we need to start using up some produce, stat.

I have "Simple French Food" open to page 285.

I have not expected to spend the evening pondering the existential nature of soup, but as the timer winds down on the suggested 30-minute cooking time, I find myself pushing a greenish floating vegetative mass around the pot, and I'm thinking to myself that Potato and Leek Soup was already going to be a tough sell, and now it looks as if I will be trying to market boiled Eurasian milfoil to an 11-year-old and a high school junior.

I'm willing to give this a little bit longer, because we have just recently tried Olney's Cotriade, or Breton chowder, which has instantly become a household staple — a simple fish soup that everyone in the family, fish-faithful and fish-agnostic alike, will eat with hunger. So I'm willing, as I say, to give this Olney a little more leash, but I'm also mentally gathering the ingredients for the Plan B pasta dish.

Then, something a little bit magic happens. Just before serving, as instructed, but with dying hope, I stir in three tablespoons of butter, and the next taste from the wooden spoon is suddenly and undeniably a taste of Potato and Leek Soup, and not the previous thin parade of vaguely salty veggieness.

The butter, the unassuming fifth and final ingredient, has served as a liaison. Most often, it's cream and egg yolks, but the effect is the same: An animal fullness has melted into the spaces between the ingredients, and the butterfat and protein now carry a little bit of all the rest of the flavors with them into every corner of the pot, making something whole out of what had been, until then, unsatisfyingly separate.

I pour the soup into four bowls, over croutons of toasted baguette, and serve it to my demanding clientele, who silently devour everything in minutes, and then disperse to resume their homework, as if a small miracle has not just occurred in our midst. I set a log on the fire, pour another glass of wine for my wife, Mary Jo, and myself, and say a little secular prayer to the eloquently opinionated hermit of Solliès-Toucas.

Steve Hoffman is a Twin Cities tax preparer and writer, and an occasional French villager.