Grilled Cheese Sandwich with Tomato & Onion

Today I was craving something simple, yet tasty.  This Grilled Cheese Sandwich with Tomato and Onion was a perfect combination of ingredients.  Of course if the tomatoes had been homegrown from this summer it would have been better, but I did my best with what I had at hand. (Guess I will just have to make this again come July!)

Ingredients:
1 slice Cheddar Cheese (or 1/4 cup shredded cheese)
1 slice Mozzarella Cheese (or 1/4 cup shredded cheese)
Parmesan Cheese
2 slices Wheat Bread
2 Red Onion slices
Tomato- variety of your choosing
(I used several grape tomatoes I had on hand)

Instructions:

STEP 1: Butter both sides of the bread.  

STEP 2: Layer with Cheddar, Mozzarella and Parmesan cheeses.    

Cheese layered with Onion and Tomato

STEP 3: Cut 2 slices of Onion and Tomato and place on top of cheese.  

STEP 4: Cook for approximately 4 minutes per side or less until golden brown.

 STEP 5: Cut sandwich in half and serve warm.