CHICAGO – Most people know they should try other restaurants when they are in a great food city. I do too. And yet every time the tortilla soup arrives at Frontera Grill, that plan is out the window.

I have visited Chicago once a year since the late 1980s, usually in May for the National Restaurant Association Show. I have always seen the city as a more accessible and friendlier New York — the same world-class dining, the same energy, but without the attitude.

You can get a reservation. People look you in the eye. The host remembers your name by the second visit. Now that my son lives here as a fledgling chef, the trips happen several times a year, and the city has become more than a food destination.
It is personal now.

Rick Bayless grew up in his family’s barbecue restaurant in Oklahoma City — fourth generation in the business. He studied Spanish and Latin American culture at the University of Oklahoma, did graduate work in linguistics at Michigan, and then walked away from a PhD to do what he was born to do. He and his wife, Deann, moved to Mexico for six years to study, eat and write. In 1987, they opened Frontera Grill on North Clark Street. Seven James Beard Awards. A PBS TV show. Top Chef Masters. Nine cookbooks. None of that tells you what you really need to know: Rick Bayless is the best Mexican chef in America.

Of all the great soups I have enjoyed — and there have been many, including the mushroom soup at Paul Bocuse’s restaurant in Lyon and Frank Brigtsen’s butternut squash and shrimp bisque in New Orleans — Bayless’ tortilla soup at Frontera holds its own. It has been on the menu since opening day. Thirty-eight years. That alone says something.

From what I understand, this is how Bayless makes the magic: He toasts pasilla negro chiles and blends them with fire-roasted tomatoes, then cooks that puree with garlic and onion until it is thick and dark — almost like tomato paste, but nothing like tomato paste. Chicken stock goes in. It simmers. Thirty minutes later, the broth tastes unlike any tortilla soup at any other Mexican restaurant. Deeper. Darker. More serious. That’s the word: depth. Not heat. Not flash. Depth. The kind of flavor that hits behind your sternum and just sits there.

Then the garnishes arrive: crispy fried tortilla strips, crumbled chile, shredded Chihuahua cheese, diced avocado, crema and a squeeze of lime. Every spoonful is a different combination. You do not want it to end. And it never does, because you order it again next time — and the time after that.

Frontera still pulls me in every trip. Some things do not change. But now, when that tortilla soup comes to the table, it is not just the chiles, the broth and 38 years of perfecting a dish. My son is across the table. He has kitchen burns on his forearms and opinions about stock. We sit in a booth 800 miles from Hattiesburg, and he talks about this business the way I talked about it at his age – like it is the only thing worth doing. There is a depth to this moment that has nothing to do with pasilla chiles. It is the depth of a son who could have done anything and chose this. He is building a life in the business his father gave his life to. And he chose it freely and completely.

That is better than any bowl of soup. Even this one.

Onward.

SHRIMP AND BUTTERNUT SQUASH BISQUE

Makes about 1 gallon

Ingredients:
2 tablespoons olive oil
2 pounds shell-on shrimp, peeled and deveined, shells reserved
6 cups heavy cream
2 bay leaves
3 tablespoons unsalted butter
1 1/2 cups yellow onion, small dice
1 cup carrot, peeled, cut into 1/2-inch cubes
1/4 cup shallots, small dice
2 teaspoons garlic, minced
4 cups butternut squash, peeled, seeded, cut into 1-inch cubes
2 cups chicken or seafood stock
1 tablespoon kosher salt
1/4 teaspoon white pepper
1/4 teaspoon cayenne pepper
1/4 cup orange juice
6 ounces thick-cut bacon, 1/4-inch dice
1 pound lump crab meat, shells removed
1/4 cup chives, chopped

Instructions:
■ In a 3-quart saucepan, heat olive oil over medium-high heat. Add shrimp shells and sauté until bright orange, about five minutes. Remove from heat. Pour cream over shells, add bay leaves, and simmer on low for five minutes. Let shells steep while preparing the rest of the bisque.
■ In a 6-quart stockpot, heat butter over medium heat. Add onions and carrots and sauté about five minutes, until onions are translucent.
■ Add shallots, garlic and butternut squash. Cook three minutes, stirring occasionally.
■ Pour in stock, cover, and steam seven to eight minutes until squash begins to soften.
■ Strain cream over the squash mixture, pressing on shrimp shells to extract flavor. Discard shells and bay leaves. Bring soup to a simmer and cook seven to eight minutes until squash is tender.
■ Add salt, white pepper, cayenne and reserved peeled shrimp. Simmer six minutes, then remove from heat. Let cool 10 minutes.
■ Puree soup in a blender or food processor until smooth. Stir in orange juice and keep warm.
■ In a medium skillet over medium heat, cook bacon until golden and crispy. Drain grease. Add crab meat and cook just until warmed through. Remove from heat and stir in chives.
■ Pour bisque into serving bowls and top with bacon and crab mixture. Serve immediately.

Robert St. John is a restaurateur, author, enthusiastic traveler, and world-class eater from Hattiesburg, Mississippi. He has spent four decades in the restaurant industry, written 13 books, and written a syndicated newspaper column for more than 24 years. Read more about Robert at robertstjohn.com.