Prepare boiling water canner, jars, rings and lids as described above.

In a large stainless steel saucepan, combine wine, vinegars, water, sugar, oregano, basil and garlic. Bring to a boil over medium-high heat and cook until sugar dissolves, around 2 to 3 minutes. Add tomatoes and onion; return to a boil and continue cooking at a boil for 5 minutes. Season to taste with salt and pepper.

Ladle hot tomato mixture into hot jars, leaving 1/2-inch space between the top of the food and the rim of the jar. Remove air bubbles; add more tomato mixture as needed to keep headspace at 1/2 inch. Wipe rims clean; place lids on jars and screw on rings. Place jars in canner covered by at least 1 inch of water. Bring water to a boil and process jars over high heat for 20 minutes from when the water begins to boil - remember high altitude adjustments if needed (see above). Turn off heat and let jars rest in canner for 5 minutes. Remove and place on a clean dish towel to cool. Let rest undisturbed for 24 hours.

When ready to serve, drain off some of the liquid (otherwise I found it to be a bit too runny) and serve over brie or goat cheese on toasted baguette slices.