If you are unable to find green tomatoes, you can use other types. The tomatoes can be refrigerated, in the liquid, in airtight containers for up to 10 days.
Bring all ingredients except tomatoes to a boil in a stockpot. Reduce heat, and simmer 15 minutes. Add tomatoes; cook 3 minutes. Remove from heat, and let cool completely in the brining liquid. Serve chilled or at room temperature.