Doug Sohn, owner of Hot Doug's. Photo: William Couch/ Flickr.

Frankfurter maestro Doug Sohn, the man behind the beloved Chicago eatery Hot Doug's, is a stickler for putting the same care into his hot dog toppings that a top chef would a béarnaise sauce.

"Whatever you pair, you want it to taste good," he says. "We caramelize our onions in real butter. We get the freshest tomatoes."

Sohn is a trained chef who bypassed life in a haute restaurant to grill haute dogs. He's been on the wiener beat for nearly a decade, and remains an undeterred champion of foie gras in the wake of a since-overturned Chicago-wide ban. His sought-after pups feature tantalizing names like the "mighty hot" Keira Knightley and the "mighty, might, mighty hot!" Salma Hayek andouille sausage.

With grills heating up for the Fourth of July, here are Sohn's thoughts on how to spruce up that old dog.

Sohn on bringing his own dogs to Cubs games and the awesomeness of foie gras franks after the jump.

Is there an art to topping a hot dog?
Yeah. It's the same art as topping anything else. What's the difference between this and fine dining? Make it hot, make it good and get it out of the kitchen. You want to make sure that anything you put on a sausage is good.

What is your favorite hot dog topping?
Mustard.

Why?
I love mustard, and l love the combination of the tangy mustard and the saltiness of a hot dog.

What are some of the more bold toppings you have put on a hot dog?
Foie gras is a little bit unusual. We have put sautéed plantains on a hot dog. We do truffles every so often and those work. Sauternes.

What is one topping you would never put on a hot dog again?
There are no food rules. I know it's a big thing to not put ketchup on a hot dog in Chicago, but if you like ketchup on your hot dog, put ketchup on your hot dog. I know this is going to be blasphemous in Chicago, but if I am at a picnic and ketchup is the only topping, I would put ketchup on a hot dog. It's not my first choice.

Where did Chicago's "no ketchup" trend come from?
I am not sure when that started. I understand it ... that the sweetness of the ketchup does not match up with the sharpness of the hot dog. I agree that it is not a good match. There are places that refuse to serve it. I am not one of them.

What is the best way to prepare a hot dog?
I tend to like them chargrilled ... I like the way the skin crisps on the grill and breaks a little bit. A deep-fried dog is darn good. A steamed dog, I love the way the skin firms up.

Despite knowing how hot dogs are made, why do we have such a love affair?
It's sort of one of those myths. A good hot dog, and we use Vienna Beef hot dogs which are local ... they are using brisket. I have seen them make it. It's not a huge deal. It's associated with happy things ... baseball games ... picnics ... Fourth of July.

What makes the hot dog such a perfect grillable food?
It's meat, salt and fat in one little package. It satisfies the basic human taste. It's really easy to make. ... It's really accessible. If someone gives you a hot dog on a bun, you know what to do with it.

How many hot dogs a year do you eat?
My guess is over the course of the year, 30. Every couple of weeks I will certainly have one. If I go to a Cubs game, it usually goes up. I usually bring a couple of my own and eat two to three during the game. They may have the worst ballpark hot dogs in the country.

Do you eat hot dogs on July Fourth?
If they are there, absolutely, but I don't make it a specific point.

What's the craziest hot dog you have had?
Sonoran dog -- mayonnaise, pinto beans, chopped onions and chopped tomatoes. Any time you put mayo on meat, you think it's not going to be good, but it's usually good. Well, except on corned beef. That's the one rule.

So how is foie gras on a dog?
It's delicious. I am pretty sure foie gras on anything is pretty delicious. There are certain items like bacon, cream, foie gras and salt. Cheese might be one of those things too. I can't think of a food that would not be better with any of those on them.

What kind of effect has your outspoken reaction to the foie gras ban had on you and your business?
This was now a couple of years ago. The publicity was not what I expected. My goal was to simply be a smart ass in all of this. It was a fascinating time and fascinating to see what was going on in Chicago at the time. Unless you are a vegan, I don't see the difference between eating foie gras and eating eggs, the way things are processed in this country.