How to Make It
Stir together yogurt, olive oil, vinegar, lemon zest, lemon juice, salt, and pepper in a bowl. Chill until ready to use. Fill a large bowl with ice water.
Cut each head of broccoli in half lengthwise. Bring 1 inch of water to a boil in a large saucepan fitted with a steamer basket. Arrange the broccoli halves, cut side up, in basket. Cover and steam until tender-crisp, 6 to 7 minutes. Transfer broccoli to ice water bath, and let sit until chilled, about 3 minutes. Drain well. Cut the florets and stems into bite-size pieces to equal about 8 cups.
Combine broccoli and onion in a large bowl; toss with dressing. Add parsley, almonds, and dill; gently toss.