4 cups spinach, washed, dried and torn into bite-sized pieces
2 cups escarole, washed, dried and torn into bite-sized pieces
6 button or Cremini mushrooms, stems trimmed and thinly sliced
1 celery stalk, thinly sliced
1/3 cup olive oil
2 tablespoons Meyer lemon juice, or regular lemon juice
1 small clove garlic, minced
1 teaspoon whole grain mustard
Combine spinach, escarole, mushrooms, and celery in a large salad bowl.
Combine oil, lemon juice, garlic, mustard and a good-sized pinch of kosher salt and freshly ground black pepper in a glass jar with a tight-fitting lid. Shake vigorously to combine. Drizzle half the dressing over the salad, toss and add more if necessary. Taste and season with more salt and pepper if desired.