Pour vinegar in a medium sized bowl.
Add garlic and onion.
Marinate for 15 minutes.
Taste to determine if sugar is needed, add a tiny bit at a time until mixture is not too tart.
Add the basil, tomatoes, salt and pepper.
When water is boiling, drop the pasta in and cook for 5 minutes if using dried pasta, or for only 2 minutes if using fresh pasta.
Taste to make sure pasta is not over-cooked beyond al dente.
Drain pasta.
Toss pasta with the tomato mixture.
Top with parmigiano cheese.