This salad partners well with the chicken sauté and can be served before, after, or at the same time as the main course. Many supermarkets sell prewashed and trimmed spinach in plastic bags. The greens usually don’t need washing and stay fresh for several days in the refrigerator. Refer to the dressing as a “Dijon vinaigrette” rather than “vinegar, oil, and mustard dressing” if you need to impress someone!
2 bunches (about 10 ounces each) spinach
8 ounces white or brown mushrooms
1/4 large (1 to 2 ounces) red bell pepper seeded and deveined
Small piece (1 to 2 ounces) red onion
1/4 cup extra-virgin olive oil
1 tablespoon red wine vinegar
1 tablespoon Dijon-style mustard
1/2 teaspoon granulated sugar
Scant 1/2 teaspoon salt plus more to taste
Freshly ground black pepper to taste
Trim spinach by cutting off bunch of stems just behind leaves. Some leaves will still have short stems. If your life seems too simple, remove them; we think they taste fine and add crunchy texture. Fill a clean sink or very large bowl with cool water, toss in spinach, and agitate with your hands to encourage dirt and sand to fall to bottom of sink or bowl. Transfer spinach to a colander, then drain sink or bowl to remove grit. Repeat. Dry spinach in a salad spinner or with paper towels, and refrigerate in a plastic bag until serving time. Brush mushrooms with a bit of paper towel or a soft mushroom brush, and trim stem ends if they are dark. Cut each mushroom through stem into quarters if small, or into 6 to 8 pieces if large, and set aside. Thinly slice bell peppers, and set aside. Thinly slice onion, and set aside.
To make dressing, in a small jar with a tight-fitting lid, combine olive oil, vinegar, mustard, sugar, salt, and pepper. Cover tightly and shake vigorously to blend ingredients.
When ready to serve, place spinach, mushrooms, pepper, and onion in a large serving bowl. Give dressing a last-minute shake and pour over salad. Toss, taste for seasoning, and add more salt or pepper, if desired. Serve at once on individual salad plates.