For the salad: To mellow the minced onion, soak it in cold water for 10 minutes, then drain well, pat dry, and put in a serving bowl.
Meanwhile, make the dressing: Smash the garlic clove, sprinkle with 1/2 teaspoon of the salt, and, with the side of a large knife, mash and smear the mixture to a coarse paste. Put the paste in a bowl and add the orange zest, vinegar, remaining 1 teaspoon salt, and black pepper, to taste. Gradually whisk in the olive oil, starting with a few drops and then adding the rest in a steady stream to make a smooth, slightly thick dressing.
Using a handheld mandoline or a knife, cut the fennel lengthwise into long, thin slices. Add to the onion and toss with the chickpeas, peppers, artichoke hearts, arugula, parsley, and dressing. Scatter the olives and shave the Parmigiano-Reggiano over the top.
Shopsmart: Baby arugula has smaller, more tender leaves and a slightly less peppery and assertive flavor than "grown-up" arugula.
Know-How: Parmigiano-Reggiano shavings are a simple way to add texture, taste, and eye appeal to salads. To make them, hold the cheese firmly in 1 hand and run a vegetable peeler firmly across the longest edge of the cheese to peel off long, thin strips.