Sauté the Onion:

1. Melt butter in a skillet over medium heat. Add the chopped onion and sauté until translucent and fragrant, about 3-5 minutes.

Combine in Crock Pot:

1. Transfer the sautéed onion into the crock pot.
2. Add the cream of chicken soup and milk, stirring well to combine.
3. Add the cubed Velveeta cheese and frozen chopped broccoli.

Cooking:

1. Set your crock pot to low. Cover and let the soup cook for 3-4 hours.
2. Stir occasionally to ensure even melting of the cheese and to prevent the soup from sticking to the bottom.

Final Touches:

1. At the end of cooking, adjust the soup’s seasoning with salt and pepper to taste.
2. If desired, blend using an immersion blender for a smoother texture before serving.