In a bowl mix together chopped onion, tomato and basil. Add olive oil, garlic salt, salt and black pepper to taste.
Mix everything till well combined and then set aside for 1-2 hours. This time is important for flavors to mix-in together.
In a plate take olive oil and add minced garlic to it. Also add salt, black pepper and mix.
Dip the bread slices one by one in this oil-garlic mixture. Toast the bread in the oven at 350 F degrees for 8-10 minutes. Or you can toast on a grill/pan.
While you are toasting the bread, make the balsamic glaze. To a pan on medium heat, add balsamic vinegar and maple syrup. Also add pinch of salt & black pepper (optional).
The mixture will come to a boil, keep stirring till it thickens. This will take 4-5 minutes. You will know it's done when it coats the back of your spoon.
Arrange the bread slices on serving plate. Top with the onion-tomato-basil mixture.
Drizzle the balsamic glaze on top, sprinkle some more basil and serve the onion tomato bruschetta immediately!