In liquid measuring cup, whisk together vinegar, mustard, salt and pepper. While whisking, slowly drizzle in oil until all oil is incorporated.
Place cucumber in one small bowl; place tomatoes and basil in second small bowl. Divide vinaigrette between cucumber and tomato bowls; stir both mixtures, separately, until well combined.
In sixteen (2-ounce) shooter glasses, layer cucumber mixture, cheese and tomato mixture. Serve immediately.
This website provides estimated nutrition information as a courtesy only. You should calculate the nutritional information with the actual ingredients used in your recipe using your preferred nutrition calculator.