Spinach, Grapefruit, and Avocado Salad with Poppy Seed Dressing

Ingredients

• 2 pink grapefruit
• 1 tablespoon white-wine vinegar or rice vinegar
• ¼ cup finely chopped shallot (1 large)
• 2 teaspoons poppy seeds
• 1 teaspoon honey
• 1 teaspoon Dijon mustard
• 3 tablespoons extra-virgin olive oil
• ½ teaspoon salt, or to taste
• Freshly ground pepper to taste
• 8 cups (6 ounces/170 grams) baby spinach, rinsed and dried
• 1 cup sliced radishes (1 bunch)
• 2 avocados, peeled, pitted, and sliced