Pairing tomatoes and peaches in a dish just sounds wrong; the combination reminds me of a mismatched couple. Yet, like many unlikely (yet joyful) relationships, timing and maturity are everything. The natural sweetness of the tomato, which is actually a fruit, comes to its prime at the same time as that of the peach. Therefore, I would only pair tomatoes and peaches at this time of year. Feel free to experiment with the vinaigrette but using perfectly ripened Michigan tomatoes and Michigan peaches is essential and not up for negotiation.
I enjoy the flavor of walnuts or pecans with tomatoes and peaches but they can be omitted. Likewise my nutty vinaigrette may be changed to a classic balsamic vinaigrette.
My favorite vinaigrettes often begin with minced shallot macerated in vinegar. “Macerate” is a word that means to soften while soaking in a liquid. It mellows out the flavor of the shallot and permeates the vinaigrette in a classically subtle, palate-pleasing manner. This salad warrants only a very small vinaigrette as it’s basically an uncooked peach compote, but in general, I still use less than 1/2 teaspoon of minced shallot to dress a salad for 4; add more if you prefer a stronger shallot flavor. If you’ve extra vinaigrette, I would advise straining out the shallot as the flavor blooms as it rests in the vinaigrette.