On the surface, Michael Recchiuti’s new book “Chocolate Obsession” (Stewart, Tabori & Chang, $35) seems to have about as much in common with Paula Wolfert’s reissue of her 1982 classic, “The Cooking of Southwest France” (Wiley, $37.50) as, well, cocoa and cassoulet. Mr. Recchiuti is a modern chocolatier working in the new wave style. Ms. Wolfert is a traditional French food expert, digging up the very best recipes of a particular region. But they are kindred spirits in their insightful approach to ambitious recipes.

The lessons in “The Cooking of Southwest France” come from generations of chefs and home cooks. The book is so deep and rich that it ranks alongside other regional-food classics by Madhur Jaffrey, Marcella Hazan, and Diana Kennedy. First published in 1982, its re vised edition (with 60 additional recipes) is better than ever. Ms. Wolfert spent years in southwest France hobnobbing with chefs and home cooks, tasting, and gathering recipes that make the most of rich ingredients: duck, goose, cabbage, cream, truffles, walnuts, and Armagnac. This is food that toes the line between rustic and sophisticated, with dishes like cassoulet with fava beans, cepe and walnut cream tarts, and battercake with fresh pears.

“Chocolate Obsession,” on the other hand, thumbs its nose at tradition in the world of chocolate. Mr. Recchiuti, owner of San Francisco’s famed Recchiuti Chocolates, is one of the masters of modern artisanal chocolate-making. He flavors his ganache squares, truffles, and other chocolate treats with flavorings like jasmine tea, cocoa nibs, cardamom, and tarragon rather than more traditional liqueurs. High-end chocolate manufacturers have begun making chocolate with increased cacao percentages, but as Mr. Recchiuti points out, “These new chocolates are bursting with flavor, but their contemporary composition changes the way they react in recipes.” New chocolate demands new recipes, and “Chocolate Obsession” delivers.

But despite their differing approaches, both authors are exceptional at conveying their knowledge to readers. Duck confit, for example, is central to the cooking of southwest France, and Ms. Wolfert manages to make its preparation accessible, offering recipes for stovetop, slow cooker, and even vacuum pouch methods. Tempered chocolate is just as essential to chocolate-making, and Mr. Recchiuti’s recipe accounts for the increased cacao percentages in the new types of chocolate. Both books are well larded with history, lore, and ingredient information as well. “The Cooking of Southwest France” includes extensive sidebars on the time-honored food products of the region, from Cantal cheese and truffle hunting to a “moutarde violette” flavored with grape juice, while “Chocolate Obsession” offers a terrific crash course in the history of chocolate.

If all this is sounding overwhelming, it needn’t be. I found plenty of terrific recipes in both books that are diabolically tempting but easy on the home cook. Mr. Recchiuti devotes several chapters to easier fare like “Snacks” (devil’s food cupcakes with white chocolate-espresso topping), “Drinks” (milk chocolate with burnt caramel), and simple chocolate barks. Ms. Wolfert tracks down many simple recipes, like saute of chicken with peppers, ham, and tomatoes, and she has a gift for elemental combinations that make me dreamy, including broiled marinated duck breasts, pureed celery root with apples, and deep-fried celery leaves.

So despite the girth of both books, neither is an unapproachable vanity project. Ms. Wolfert and Mr. Recchiuti are encouraging rather than intimidating, and both share plenty of trucs (French for tricks) acquired over a lifetime of experience in their fields. Ms. Wolfert puts it best: “It is these little details that I call the ‘finesse of cooking,’ which to me is its joy.” And when it comes to big-ticket subjects like these, trucs are worth their weight in both types of truffle.