To Make the Glaze:

1. Put the balsamic vinegar in a small saucepan and bring to a boil on high heat.
2. Once boiling, reduce the heat to medium low and simmer until it has reduced to about 1/2 and coats the back of a spoon, which is about 5-10 minutes.
3. Transfer to a bowl and set aside to cool (It thickens once cool.)

For the Tomatoes:

1. Cut a large circle into the tops of the tomatoes and use a small spoon to follow each one out, making sure you don’t through the bottom or sides.
2. If the tomatoes are wobbly, you can cut the bottoms flat, but make sure you don’t go through the tomato. Sprinkle 1/4 teaspoon of sea salt inside each tomato.
3. Drizzle 1/2 tablespoon of balsamic vinegar on the inside of each tomato and then pack each tomato with 1/2 can of tuna.
4. Drizzle each tomato with another 1/2 Tablespoon of vinegar and then 1 teaspoon of olive oil.
5. Garnish with basil and DEVOUR!