Cut chicken into strips approximately 3 x 1 inch (about the size of your finger).
Roll up each chicken strip in a slice of beef.
Place the beef-wrapped chicken strips in two rows in a 9x16 baking dish.
If you have any leftover chicken, cut it up and add it to the dish.
Mix sour cream and mushroom soup together until well combined.
Spread the mixture over the chicken rolls. (The mixture will be thick but will thin out as it cooks, forming a nice gravy.)
Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius).
Bake until brown blisters start appearing on top, usually around 40 to 45 minutes. Keep checking to avoid overcooking.
Serve with wild rice, noodles, mashed potatoes, or peas. My family prefers it with mashed potatoes and peas.
This dish can be made ahead, stored in the fridge, and baked later.