Heat up a griddle or sauté pan and add a drizzle of oil and one spray of Pam (this will ensure that nothing sticks). Add onions and cook over low heat to caramelize. While the onions cook, in a small saucepan cook cheese whiz over low heat. Remove onions from pan and set aside.
To the hot griddle or pan, add 3 thick slices from your tomato and cook each side until soft; remove and reserve. Add ribeye to the hot griddle and cook until done, about 90 seconds each side.