Preheat oven to 400°F.

Meanwhile, cut the puff pastry into 1”x1” squares and place on a parchment-lined baking pan. Brush tops of puff pastry squares with beaten egg. (Optional: Sprinkle tops of puff pastry squares with a bit of black pepper.) Bake at 400°F for 14-16 minutes, or until golden brown. Remove from oven and set aside.

Meanwhile, using a medium saucepan, fill half full with water. Place over high heat and bring to a boil. Add the potatoes, carrots, peas, celery, and corn; cook for 12-14 minutes or until potatoes are tender. Remove from heat and drain. Transfer vegetables into a large bowl; add cooked chicken and stir until well combined. Set aside.

Using a large stockpot or Dutch oven, add the butter and place over medium heat. Once butter has melted, add onions and garlic. Sauté, stirring occasionally, until onions begin to turn translucent (about 6-8 minutes).

Add flour, salt, pepper, chicken stock, water and half-and-half; stir until well combined. Cook over medium heat, stirring often, until mixture begins to boil. Add vegetables/chicken and stir until well combined; remove from heat.

Divide soup into bowl and top with puff pastry ‘croutons’ before serving.