This Tex-Mex favorite is enjoyed with nachos, tacos, or chili. The carrots and green beans would also make good stirrers for a Bloody Mary. Drop onions into boiling water for 15 to 30 seconds to make them easier to peel.
Bring first 3 ingredients to a boil in a large saucepan. Add carrots to pan; cook 2 minutes. Add onions; cook 1 minute. Add pepper slices; cook 1 minute. Add beans; cook 1 minute. Remove from heat; stir in vinegar. Let stand at room temperature 1 hour. Pour into a large bowl; cover and refrigerate 24 hours. Store in an airtight container in refrigerator up to 2 weeks.