The secret to real pho is the stock

Great food doesn't come solely from the recipes. It comes from the techniques within those recipes. For instance, learn to make a good stock and you can do dozens of soups. This is how Vietnamese chef and restaurateur Charles Phan thinks about cooking.

Phan is the chef and owner of The Slanted Door restaurant in San Francisco, and his first cookbook, Vietnamese Home Cooking, is a guide for anyone who wants to learn the techniques of Vietnamese cooking.

Recipe: Lynne Rossetto Kasper's beef pho.

Lynne Rossetto Kasper: The Vietnamese soup pho is an incredibly fragrant and delicious beef broth with rice noodles, and then you have all of these things you can add: the vegetables and the seasonings. But the stock for this is everything, right?

Charles Phan: If you understand the stock and how to harness all the flavor from your bone, it's super important. This is the basis.

It is one of the favorite things in the kitchen when we [chefs] eat. If you look at the one food that kitchen folks eat more than anything else, it is noodle soup.

Charles Phan's recipe for Chicken Pho.

LRK: How do you do that beef broth?

CP: In Vietnam, we generally don't have ovens, but we still need to make this broth be clear and flavorful. So instead, we blanch the bone. It takes 30 to 60 seconds, then you rinse it in cold water and put it back in your pot. Bring it up really slow -- never a super hard boil. This is to achieve clarity.

To achieve the flavor, use different kinds of bone. For instance, in the beef, you would use the oxtail, the shank bone, the neck bone.

LRK: One of the things you do in the beef broth is take a whole onion, cut it in half, and roast it with a chunk of ginger in the oven for an hour while you're blanching the bones. Does that deepen the flavor of those ingredients?

CP: What you're doing is caramelizing the onion. Just like in a pasta sauce, you will brown the onion first before you put in the tomato. It's sort of the same concept. You need to get that caramelization of that sugar, and the flavor of the ginger also heightens.

LRK: It sings when you roast it. The other components of this broth are sugar, cinnamon, star anise, clove and cardamom. They all get simmered. I think that's where all those mysterious rich flavors come in.

So once you've got the broth, how do you put together the pho?

CP: Classically, a beef pho is done with a rice noodle -- never an egg noodle. Egg noodle is more like a Chinese wonton import. You can use dried noodle or fresh; it's up to you.

Blanch the noodles and do not overcook. Put the noodles in a warmed bowl. Put your raw meat on top of the noodles and add your garnish. Then ladle your broth on the side, not touching the utensil to the raw meat. Bring the broth up to the level just covering the meat.

We serve it with a lot of herbs and vegetables, like bean sprouts to create different textures. We take the aromatics very seriously. The basil and the lime, for instance, we don't add all at once. We put them in a few pieces at a time. Let the hot soup melt the herb so you get the aromatic flavor and the smell of the herb. Of course, you have sriracha dipping sauce on the side.

The Vietnamese sensibility is not just on the flavor of the soup but also how you smell the fresh herbs.