For the vinaigrette: Place the oil, vinegar, shallot, salt and pepper in a serving bowl and whisk to combine. Prep ahead tip: at this point, the vinaigrette can rest as room temperature for up to 2 hours.
For the salad: Pat the rinsed and drains beans dry. (For ease, I like to dump them in a tea towel and roll them around for a few seconds.) Drying the beans will reduce popping while cooking.
Heat the oil in a large skillet (a 12-inch diameter allows room to spread the beans out) over medium-high heat. Add the garbanzo beans and spread into a single layer. (Tip: If you have a spatter guard, it will keep the area around your burner clean.) Cook undisturbed until lightly browned on the bottom, 3 to 4 minutes.
Stir, sprinkle evenly with ¼ teaspoon of salt, and spread the beans out again. Cook for another 2 minutes, then stir and spread out again as needed, until golden-brown, adding the cumin in the final minute to lightly toast it. From start to finish, cooking the beans will take 6 to 7 minutes. Taste for doneness: you want the beans to be flavorful and just a tad crisp on the outside but still a little soft in the middle. Remove from the heat.
Add the cooked bean mixture (scraping out the cumin seeds – they taste great!), tomatoes, and parsley to the vinaigrette in the bowl, and toss to combine.