Bring a large pot of water to boil and add the cauliflower and carrots. Let cook for 2-3 minutes, add the broccoli. Cook an additional 2 minutes until vegetables are crisp tender.
Drain the vegetables without rinsing.
Heat oil in a large skillet over medium high heat. Add the spices and let sizzle for a second or two before adding the steamed vegetables and red onion. Let cook just a minute or two until the spices are distributed and the onions have started to wilt.
Toss in the vinegar and lemon zest and transfer the salad to a serving bowl. Allow the salad to stand for 10 minutes before serving.