Melt butter in a large frying pan over medium heat. Spread cream cheese on 1 side of 1 bread slice. Put slice in pan, cream cheese side up, and the other slice alongside. Scoot both around so they absorb the butter.
Reduce heat to low. Top cream cheese slice with fontina and the plain slice with cheddar. Cover pan and let cook 1 to 2 minutes, or until cheeses are melted. Transfer to a plate.
Cover fontina-topped slice with artichoke mash, olives, and tomato. Top with cheddar slice.
Note: Nutritional analysis is per sandwich.