Watermelon Avocado Spinach Salad with Poppy Seed Dressing

For the Poppy Seed Dressing:

• 1/4 cup white balsamic vinegar or champagne vinegar
• 3 tablespoons honey
• 2 teaspoons poppy seeds
• 1/2 teaspoon kosher salt
• 1/4 teaspoon ground mustard
• 1/2 cup olive oil

For the Salad:

• 6 cups spinach fresh
• 2 cups watermelon seedless, pieces
• 1 avocado peeled, pitted, and sliced
• 1/3 cup feta cheese crumbled
• 1/4 cup  almonds roughly chopped
• red onion thinly sliced, half small