Mince the garlic. If you have a garlic press, use it to get 2 cloves worth of paste. If you don’t, just chop it up as fine as you can – you want the finished product to be smooth.
Sauté the garlic in half a tablespoon of olive oil for 1 minute, until soft.
Add the onion, and sauté 2 minutes more.
Then add a half teaspoon of salt and another tablespoon of olive oil; sauté 1 more minute.
Then add the oregano, balsamic vinegar (1 Tbsp each), water (or chicken broth), wine or broth (2 Tbsp each), and any other seasonings you prefer.
Bring to a boil, then reduce heat and simmer for 10 minutes.
Place all the ingredients in a blender or food processor until smooth.
Add salt and pepper to taste. Pour into the remaining oil, and heat until warm (but not hot).