With mushrooms, there is no equivocating. People either love them or hate them. The division may have as much to do with texture as taste.

When not thoroughly cooked, mushrooms can be slimy or mushy. But, when slowly roasted in a moderately hot oven, they turn amazingly dense, dark and earthy-tasting, often compared to a good cut of beef. Done this way, even the most resistant mushroom haters can be converted, especially when portobellos are put into play.

Portobello mushrooms are simply big cremini mushrooms — which are mature white button mushrooms. In short, white button, cremini and portobello are all the same variety. Portobellos are the biggest, brownest, firmest and most flavorful of that variety. (The names "portobello" and "cremini" were created to make these mushrooms sound more exotic than "mature white button mushroom.")

When shopping for mushrooms, avoid those that look soft, broken or deteriorating. When you get them home, remove them from plastic bags or their wrappings, and store them in a brown paper bag or covered in a paper towel.

There is some debate over cleaning. Washing? Wiping? Dusting them off with a mushroom brush? Julia Child washed her button mushrooms on TV, so I usually just go ahead and give them a quick dunk in cold water, then pat them dry with a paper towel or clean dishcloth. Do this just before cooking, not ahead of time.

When preparing portobellos, snap off the stems and reserve for a stock, then remove the "gills" on the underside of the cap with a teaspoon or dull knife. These tend to hold dirt and trap moisture, so by scraping them off you get a cleaner taste.

The key to cooking portobellos (or any mushroom) is to allow enough time to draw out most of their moisture. Whole portobellos require at least an hour. Cut them up and they're ready in half the time, about 30 to 45 minutes. At that point, when they're firm and very dark, they're great in pasta, on pizza or served on brown rice. Roast portobellos, toss with spinach and tangy mustard vinaigrette, and call it lunch.

Roast Portobello and Spinach Salad With Tangy Mustard Vinaigrette

Serves 4 to 6.

Note: Roast a chopped red bell pepper and leek along with the mushrooms to add color and flavor to this dish. Make a double batch for tossing with pasta, topping pizza or bruschetta. From Beth Dooley.

• 2 lb. portobello mushrooms

• 1 large leek, white part, sliced in half lengthwise

• 1 medium red bell pepper, cored and seeded

• 2 to 3 tbsp. extra-virgin olive oil

• 1 tsp. coarse salt

• Pinch red pepper flakes

• 5 to 6 oz. spinach

Vinaigrette:

• 1 tbsp. chopped shallot

• 1/3 c. extra-virgin olive oil

• 2 tbsp. fresh lemon juice

• 1 tsp. Dijon mustard

• 1/2 tsp. honey

• Salt and freshly ground black pepper, to taste

Directions

To roast the vegetables: Preheat the oven to 375 degrees. Stem the mushrooms (reserving the stems for another use, such as stock). Using a teaspoon, scrape the underside of the mushrooms to remove the gills. Dunk quickly in cold water and set on paper towels and pat dry. Cut into 1/2-inch chunks.

Run the cut part of the leek under cold running water and pat dry. Cut into 1/2-inch pieces. Remove the ribs from the pepper and cut into 1/2-inch pieces.

Place the vegetables in a large bowl and toss with enough oil to lightly coat. Sprinkle with salt and a pinch of the red pepper flakes. Spread the vegetables out on a flat sheet pan so that they do not touch. Roast until the mushrooms are a dark brown and very firm. Remove and set aside.

To make the vinaigrette: Place the shallot, 1/3 cup oil, lemon juice, mustard and honey into a blender, and process until smooth. Season to taste with the salt and pepper.

To assemble the salad: Place the spinach in a large bowl and toss in just enough of the vinaigrette to lightly coat.

In a separate bowl, lightly dress the roasted mushrooms with the vinaigrette and place on top of the spinach. Season with salt and pepper to taste. Serve at room temperature.

Nutrition information per each of 6 servings:

Calories210Fat17 gSodium370 mg

Carbohydrates14 gSaturated fat2 gTotal sugars5 g

Protein4 gCholesterol0 mgDietary fiber4 g

Exchanges per serving: 3 vegetable, 3 ½ fat.

Beth Dooley is the author of "In Winter's Kitchen." Find her at bethdooleyskitchen.com.