Once fall hits, something happens to cooks. Taste buds steer toward deep, hearty flavors and comfort foods, and for so many of us, that means that soup’s on.

One of my favorites is French onion soup. This time of year, it’s a constant on many restaurant menus. It’s loved for its beefy broth, sweet onions and layer of melted cheese. Add in some toasted bread, and it satisfies as a meal.

The onions, of course, are paramount, and I like a good amount of onions in the soup. In every spoonful, you should encounter onion, broth, cheese and bite of bread. That’s what brings French onion soup together.

What kind of onion to use? The most common type is the yellow onion. But you can also use white onions, sweet onions and Spanish onions. If it’s a deep flavor you’re after, try red onions. Slice them in ¼-inch-thick slices.

I like to cut them into 1/4-inch half-circles so they are discernible. If the onions are sliced too thin, you run the risk of having them cook too fast and burn or cook down next to nothing.

Start out heating some oil in a pot or Dutch oven. Make sure the onions have some space. Most recipes call for cooking down or caramelizing the onions so they release their natural sugars. When the sugars are released, the onions change color.

How dark you want them to be is up to you. A honey color to a deep amber is generally safe. Keep in mind that the darker the color, the deeper the flavor. Just be certain to keep an eye on the onions so they don’t burn. You’re aiming for a sweet taste, not a burned one. Also, don’t stir the onions a lot, or they won’t caramelize properly.

Then there is the cheese, another key part of French onion soup. The classic route calls for Gruyère, a cow’s milk cheese that has some nutty nuances. You can use several varieties, but choose wisely. French onion soup demands a good melting cheese. Options include Muenster, fontina, Havarti and provolone.

Most onion soups call for a beef broth or stock. You need to keep in mind that many store-bought broths or stocks are high in sodium. Many cheeses also have plenty of sodium. So you need to balance the two so the soup isn’t overly salty. It’s best to choose reduced-sodium varieties.