Heat a pan over medium-high heat. Sear the seasoned gyros meat until browned, about 5 minutes.
While the meat cooks, clean the leek and cut it into thin rings. Cut the large onion into thin rings.
Add the leek and onion to the pan with the meat.
Add 1 cup cream, ½ cup sour cream, and 5½ tablespoons processed cheese to the pan.
Reduce heat to low and simmer for 5 minutes.
Season with salt, pepper, and gyros spice as desired.
Serve with rice, potatoes, fried potatoes, French fries, or noodles. Serve with pita bread or ciabatta if desired. Serve with green salad or mixed salad.