There’s Nothing Like a Good Concha. Here’s How to Make Them Great.

You’ve probably seen a concha: that springy, buttery brioche-style bun covered with a crisp- tender topping traditionally molded to look like a seashell.

But have you had a great one?

Anyone who has tasted a well-made concha will go weak at the sight of a fresh one in a panadería — or really anywhere food is sold throughout Mexico and Mexican American neighborhoods. A pillar of Mexico’s culinary identity, the concha is an integral part of everyday meals and family celebrations, appearing in movies, paintings and books, and inspiring concha–shaped household items like stuffed pillows and slippers. They can be eaten for breakfast with hot chocolate, coffee or milk; snacked on as an anytime pick-me-up; or even split in half to make sandwiches.

Yet there is a good chance that a concha bought at a bakery or store will have a stale bread base with a tasteless topping. Demand for the beloved quick bite is so high that bakeries sell out anyway.

“It is mostly about staying in business,” said Irving Quiroz, a pastry chef based in Monterrey, Mexico. There is so much competition that bakers strive to offer affordable prices and make sacrifices in the process. Butter is reduced or left out in favor of vegetable shortening; water is used instead of milk; and, sometimes, the eggs are skipped entirely.

“It’s an understandable business practice, but the downside is that it makes it feel like you’re eating a sponge,” said Francisco Migoya, a Mexican chef and an author of “Modernist Bread.” “You’ll almost always see someone eating it by dunking it in hot chocolate or coffee because it is so dry.”

There are a few key characteristics of a transcendent concha: a tender yet sturdy bread base; a flavorful, crumbly topping; and a balanced bread-to-topping ratio. The good news is you don’t have to test out a dozen panaderías to find a great one. Here’s how to make a perfect concha at home.

Consider the Fat Content

Be it butter or shortening, the less fat, the drier the bun, but too much fat coats the gluten chains and can weaken them, impeding rise. Traditionally, conchas were made with fresh lard, Mr. Quiroz said, and you can still find some prepared that way, rich and layered in flavor, in small towns in the Mexican countryside.

However, conchas made with lard tend to stay flat and are quite dense. Butter, a less heavy fat than lard, doesn’t weigh down the rise, giving conchas a pillowy puff and delicate taste. (Buns made with vegetable shortening will also puff up but lack flavor.)

Most panadería conchas are 12 to 20 percent fat to flour (hence the dryness), but this recipe increases the butter content to almost 36 percent for a tender bun that still rises and hold its shape.

Knead, Knead, Then Knead Some More

Concha dough requires more kneading than might seem rational. It will appear too wet at first, but will eventually thicken.

Mr. Migoya recommends a stretch-and-fold method before letting the dough rise, as it gently develops gluten and achieves the desired smooth surface.

Look for the right consistency rather than counting minutes: You want a dough that is shiny and extremely soft; it should feel a bit like toy putty. It should sound loud as it slaps around the stand mixer bowl.

With a bit of patience to work the dough, it will be not only a vehicle for the topping, but also it will shine in its own right.

Prioritize the Topping

The best part of a concha is, arguably, the topping.

In addition to lending flavor, the topping must maintain its signature seashell shape (concha means “seashell” in Spanish) throughout the baking process. Here, vegetable shortening, not butter, does the trick. (A butter-based topping would disappear into the concha as it bakes.)

The design isn’t just nostalgic, it’s also useful: Those ridges encourage the topping to break off gradually as you take bites, rather than crumbling all at once.

While a generous amount of topping is welcome, a tender bun could collapse under its weight. An average concha tends to be 15 to 20 percent topping, but this recipe ends up with almost 40 percent topping — a thrill for concha lovers.

Recipes: Conchas | Beans, Bacon and Avocado Concha Sandwich