Food & Cooking Recipes Salad Recipes Spinach, Mushroom, and Red-Onion Salad 5.0 (3) 2 Reviews By Martha Stewart Editors Martha Stewart Editors Facebook Instagram Twitter Website An article attributed to "Martha Stewart Editors" indicates when several writers and editors have contributed to an article over the years. These collaborations allow us to provide you with the most accurate, up-to-date, and comprehensive information available.The Martha Stewart team aims to teach and inspire readers daily with tested-until-perfected recipes, creative DIY projects, and elevated home and entertaining ideas. They are experts in their fields who research, create, and test the best ways to help readers design the life they want. The joy is in the doing. Editorial Guidelines Updated on May 16, 2017 Print Share Share Tweet Pin Email Prep Time: 10 mins Total Time: 25 mins Servings: 8 A delicious Dijon vinaigrette brings all the ingredients together in this simple salad. Ingredients 1 baguette (8 ounces), cubed 6 tablespoons olive oil Coarse salt and ground pepper ¼ cup red-wine vinegar 1 tablespoon Dijon mustard 10 ounces white mushrooms, trimmed and thinly sliced 10 ounces baby spinach 1 medium red onion, halved and thinly sliced Directions Preheat oven to 450 degrees. On a large rimmed baking sheet, toss bread with 2 tablespoons oil; season with salt and pepper. Bake, tossing occasionally, until toasted, 4 to 6 minutes. (To store, keep croutons in a resealable bag, up to 1 week.) In a large bowl, whisk together remaining oil, vinegar, and Dijon; season with salt and pepper. (To store, refrigerate dressing, up to 1 week.) Toss mushrooms with dressing; let stand 5 minutes. Add spinach, onion, and croutons to bowl; toss, and serve immediately. Cook's Notes Making your own croutons is economical and easy. Toss cubed bread with a little olive oil, season, and bake until toasted. Print