Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   2                    ripe tomato -- thinly
                        - sliced
   4      ounces        cheddar cheese -- sliced
   1      medium        onion -- peeled and very
                        -- thin
                        - sliced
   3      tablespoons   mayonnaise
   4      slices        white -- wheat or multi
                        - grained bread

Preparation:

Place each slice of bread on a cookie sheet. Grill on one side until the bread is toasted. Turn the bread over. Spread each slice of bread with mayonnaise. Then divide the tomato slices evenly between the bread. Evenly place cheese over tomatoes. Place 1/4 of the onion on each sandwich. Grill until the cheese melts and the bread is slightly toasted. Let sit for 1 minute before serving.