Pour the balsamic vinegar into a saucepan over medium heat, whisk in the chili garlic paste and bring to a bubble.
Reduce the heat to a simmer
Simmer, whisking frequently, until the vinegar has thickened and reduced by 1/2
Pour into a glass container to cool
Avocados
Dice the tomatoes, chop the mozzarella, tear or chop the basil leaves and mix together
Slice the avocados in half, remove the pit
You can spoon the mixture into the avocados as they are, or scoop out a bit of the avocado to make room for more of the caprese mixture.
Spoon the caprese mixture into the avocado halves
Drizzle the glaze over just prior to serving.
Notes
If you want to take this appetizer up a notch, grill the avocado halves while the balsamic glaze is reducing. This will make the avocado creamier. Don't drizzle the glaze over the avocados until you're ready to serve them.This makes more glaze than you'll need, but I like to taste test while prepping {so none goes to waste around here!}