In a small bowl, combine the Shallot (1/4 cup), White Balsamic Vinegar (1/4 cup), Salt (2 pinch), and Granulated Sugar (1/8 teaspoon). Let stand for 10 to 15 minutes. Whisk in Extra-Virgin Olive Oil (1/3 cup). Taste. Adjust seasoning with more salt if necessary or more oil for a little less bite. Store in a glass jar. Shake well before using.
Place the Lettuce (to taste), Radish (1), Turnip (1), Snow Peas (1 bunch), Scallion (1 bunch), and Tuna (1 can) in a large bowl. Pour over vinaigrette to taste. Season with Freshly Ground Black Pepper (1 dash) to taste. Toss gently and serve.