Here’s a foolproof way to tell whether or not a restaurant’s any good: Order soup. Or bisque. Or chowder.

If it’s love at first slurp, the rest of your meal won’t disappoint.

If it’s watery, too salty or worse – canned – ask for the check. Or, at the very least, skip the seared tuna in favor of something safe.

I’ve long thought soup says a lot about the way a restaurant values food, freshness and ingredients. George Morrone, author of “Simply Elegant Soup” ($27.95, 10 Speed Press), would agree.

“I have always enjoyed taking the opportunity, as a professional chef, to elevate the status of soup on my menus, so that they are just as interesting and appealing as the other first-course offerings – and maybe even more so,” he writes in the book’s introduction.

He traces his fascination with “simple, little old soup” back to his childhood in New Jersey, when homemade soups such as pasta e fagioli, chicken and saffron broth and clam chowder were year-round staples.

My soup obsession also started early. As a girl, much to my parents’ amusement, I sampled French onion soup at every restaurant we visited. Truth be told, I think I was in it for the cheese, but I still adore it.

Fortunately, I married someone whose appreciation for soup actually surpasses mine. My husband loves to cook for company, and he elevates the soup course to an art form. He sees inspiration in everything from potatoes to parsnips, so when I brought home “Simply Elegant Soups,” his eyes lit up.

Would we try Green Asparagus Soup with Chevre-Filled Squash Blossoms? Carrot-Ginger Soup with Lime Creme Fraiche? How about a Trio of Mushroom Soups?

In the end, we settled on a Cream of Celery Root Bisque. In the cookbook, it is served alongside Lobster Bisque with a Tarragon Flan, but we skipped all that because it took us so long to find celery root that we had neither the time nor the inspiration to do the rest. No matter – it was heavenly. The next time my husband made it, he sprinkled a little lobster meat on top, which made it even better.

With ingredients such as escargot and chestnuts (which are a little hard to find locally) and a from-scratch mentality, Morrone’s recipes aren’t for everyone. This isn’t a cookbook for beginners, and you have to really love soup, which my husband and I both do.

Morrone has even included a recipe for Modern French Onion Soup with Gruyere Tuiles – a far cry from the soups of my youth. I think we’ll try that next.

Modern French Onion Soup with Gruyere Tuiles

Serves 4

For tuiles (crisp cheese wafer-thin cheese crisp):

12 ounces Gruyere cheese, coarsely grated

For soup:

2 tablespoons grapeseed oil or butter

2 pounds sweet onions, such as Maui or Vidalia, thinly sliced

1/4 cup plus 1 tablespoon sherry vinegar

8 cups homemade beef stock

Salt and cayenne pepper

For garnish:

Freshly cracked black pepper

4 small bunches watercress

To prepare the tuiles:

Preheat the oven to 350 degrees F. Line one or two cookie sheets with parchment paper. Sprinkle cheese over the paper in a single layer to form four thin rounds, each slightly larger than the diameter of the rims of the shallow soup bowls you will be using. Bake the cheese rounds until the cheese is melted and slightly golden in color, about 14 minutes. Remove the tuiles from the oven and let them cool on the sheet. The tuiles will become crispy once they cool.

To prepare the soup:

Heat the oil in a large saucepan set over medium-low heat. Saute the onions, stirring occasionally, until they begin to caramelize and turn dark golden brown in color, about 20 minutes. Add 1/4 cup sherry vinegar and deglaze the pan. Cook until the liquid is reduced by three-quarters and the mixture is almost dry. Add the stock and turn up the heat to medium high. Bring just to a boil, then turn down heat and simmer the soup for 15 minutes. Season with salt and cayenne pepper, and add 1 tablespoon sherry vinegar.

To serve, ladle the soup into warm, shallow soup bowls. Carefully rest each tuile over the rim of each soup bowl (the tuiles should not be touching the soup). Sprinkle freshly cracked pepper diagonally across each tuile and top with a watercress bunch.

Recipe adapted from “Simply Elegant Soups.”

Cream of Celery Root Bisque

Serves 4

1 tablespoon unsalted butter

1 1/2 pounds celery root, peeled and cut into large dice

1/2 leek, white part only, washed and sliced (about 1/2 cup)

2 cups homemade chicken stock

1 cup plus 2 tablespoons heavy cream

1/2 tablespoon freshly squeezed lemon juice

Salt and cayenne pepper

Melt the butter in a saucepan set over medium heat. Add the celery root and leek and sweat for about 5 minutes. Add stock and bring to a boil. Turn down heat to a simmer and continue to cook until the celery root is tender enough to puree, about 20 minutes. Add the cream, increase heat to high and bring to a boil. Immediately remove pan from heat and transfer the mixture in batches to a blender or food processor. Puree until smooth and pass through a medium-fine strainer into a clean saucepan. Season with lemon juice, salt and cayenne pepper.

Recipe adapted from “Simply Elegant Soups.”