Potato Salad with 7-Minute Eggs and Mustard Vinaigrette

Steam potatoes, covered, in a metal steamer basket set in a large pot over boiling water until tender, 20 –30 minutes, depending on size. Transfer to a plate and let cool. Meanwhile, cook eggs in a large saucepan of boiling water until whites are set and yolks are still slightly soft, 7 minutes. Drain; transfer eggs to a bowl of ice water and chill until cold. Drain and peel; set eggs aside. Toast mustard seeds in a dry small skillet over medium-low heat, tossing constantly, until seeds start to pop, about 1 minute. Transfer to a small bowl (be ready with bowl; once seeds get going, it's chaos). Whisk vinegar, mustard, and honey in a large bowl. Whisking constantly, gradually add oil; whisk until emulsified. Season with salt and pepper. Set 3 tablespoons vinaigrette aside for drizzling. Halve potatoes and add to bowl with vinaigrette. Add parsley and toss to coat; season with salt and pepper. Transfer to a platter. Halve reserved eggs and tuck in between potatoes. Drizzle with reserved vinaigrette. Top with pickles, chives, and toasted mustard seeds.