"Only a fool has the arrogance to be dogmatic about cooking, which is infinitely variable, but why can't there be a standard from which all cooks begin?" writes Michael Ruhlman in Ratio, his enlightening, just-released book.

"Only a fool has the arrogance to be dogmatic about cooking, which is infinitely variable, but why can't there be a standard from which all cooks begin?" writes Michael Ruhlman in Ratio, his enlightening, just-released book.

This slim yet densely packed volume's terse, mathematical, one-word title turns out to be extremely apt. Because while highlighting the stripped-down ingredients and proportions necessary for making everything from crepes to sausages to creme anglaise, Ratio presents often-unexpected primal links between various foodstuffs and boils recipes down into their naked numerical essentials.

With the elegance of science, Ruhlman's book makes cooking haute cuisine seem literally as easy as 1-2-3. Call Ratio an unintimidating and near-revolutionary manual of fancy classical cooking.

For example, in the integer-rich world of Ratio, a 2:2:1 fritter batter (flour to liquid to egg) will easily morph into a muffin base with the addition of one part butter. And using Ruhlman's "bedrock" shorthand for custard (2:1 - liquid to eggs), you get other sweet and savory options. Thus (as throughout the book) after stating the custard theme and efficiently explaining technique, Ruhlman begins playing with variations.

So after mastering that 2:1 custard, just a few alterations will give you a Quiche Lorraine or a (flan-like) Creme Caramel. In other words, Ratio accurately maps out the related forests of classical cuisine while also providing close-up shots of the trees of its famous dishes.

Ratio seems like a natural progression for Ruhlman. The born, bred and returned-to Cleveland resident has been writing about insider chef stuff for years, attempting to translate the secrets of high-priest cooks into digestible books for curious amateurs.

A sometime TV personality (as a traveling companion for Anthony Bourdain or, say, a judge on The Next Iron Chef), Ruhlman has written and co-authored 13 books including the vaunted French Laundry Cookbook (where Ruhlman reveals the arcane methodologies of America's most transcendent chef) and The Making of a Chef - a behind-the-scenes look at the Culinary Institute of America.

The idea for Ratio grew when Ruhlman was interviewing Uwe Hestnar, a dean at the C.I.A. (the Harvard of cooking schools), who complained about students repeatedly having to refer to several basic recipes while cooking. Hestnar grumbled that this disrupting, to-the-page enslavement prevented the budding chefs from concentrating on the big-picture art of cooking.

Claiming the "fundamentals of cooking don't change," Hestnar pored over the classics of culinary literature and, after unearthing some common physical underpinnings among them, laboriously drew up an easy-to-read chart. On it was a grid that spelled out, in simple numbers, a previously undiscovered world of food relationships and reduced-to-the-bone recipes.

Ruhlman describes first seeing this "mysteriously thrilling" document. He marveled as he saw it had Hollandaise sauce -which Ruhlman learned to make at the C.I.A. by mixing reduced and strained cider vinegar, black pepper and lemon juice into frothed egg yolks whipped with clarified butter - as simply a numerical relationship of one pound butter to six egg yolks. Ruhlman then realized that without lemon, pepper or vinegar, it's still Hollandaise, but without butter and egg yolks, it's not.

As he writes in Ratio, the moment was like "a poet compressing and polishing his words until his idea was a diamond. Hestnar has removed every extraneous element of cooking."

By subsequent experimentation, Ruhlman tightened up Hestner's building-block ratios and discovered other elemental ones of his own. This book is the user-friendly result of Ruhlman digging for these deep truths that lie beneath the buzz and flutter of classical cuisine.

On the minor downside, Ratio reads a bit textbook-y, and Ruhlman's style here doesn't provide many writerly surprises. And the limited, yet still all black-and-white, photos are fairly lackluster.

But for home cooks befuddled by complex and rambling recipes in the hallowed annals of culinary bibles, Ratio will prove to be refreshing, liberating and even invaluable. When Ruhlman's numbers game adds up to, for instance, closely aligning gnocchi to pate-a-choux (a cream-puff-like dough), the book even proves to be brilliant in its simplicity.

Recommended for: intermediate-level Franco-leaning cooks, techie types and reference book savants.