A quick pickle gives the mangos in this salad an addictive and pleasant bite. Sweet and sour elements of the pickling liquid then form the base for the vinaigrette, and a bit of goat cheese rounds out the flavors of the dressed greens. Try this tonight.
Place the mangos, tarragon, thyme, and black pepper in a large heat-safe bowl and set aside. In a small saucepan, combine the remaining ingredients and bring to a simmer over medium-high heat.
Pour the hot vinegar mixture over the mangos and let cool to room temperature, about 30 minutes. Cover the bowl with plastic wrap and refrigerate overnight. The mangos keep up to 1 ½ weeks in the refrigerator.
In a small bowl, combine 1/3 cup of the mango pickling liquid and the olive oil. Season with salt and pepper, to taste, and whisk together. Divide the salad greens and fennel among 4 plates. Sprinkle each plate with ¼ cup of the pickled mangos, then drizzle the vinaigrette over the salad. Top with the crumbled cheese and serve.