For the salad, place the spinach on a large platter. Top with all the chopped ingredients, which include strawberries, hard cooked eggs, avocado, basil, carrots, onion, chicken, and cucumber.
For the dressing, combine the sugar, vinegar, olive oil, yogurt, and poppy seeds together in a jar. Mix very well until combined and smooth. Place in a small dish.
Serve the dressing alongside the salad for a buffet meal. Serve with crunchy bread.