Cut onion, carrot, potato, and broccoli into bite-sized pieces.
Cut the chicken into easy-to-eat pieces.
Melt butter in a pot and sauté the onion and chicken.
Add the vegetables and continue sautéing.
Add flour and stir-fry until everything is well mixed.
Add milk, water, and chicken stock, and bring to a boil.
Simmer over medium-low heat until the vegetables are cooked.
Season with heavy cream, salt, and pepper.