Preheat oven to 450 degrees F.

In a large bowl, toss cauliflower, 1 Tbsp. olive oil, cumin, chili powder, sea salt and pepper. Transfer to a baking sheet and roast for 15 minutes or until golden brown.

Remove from oven; set aside for 10 minutes to cool.

Meanwhile, steam corn in a steamer basket over medium heat on the stove top until tender, about 4 minutes.

In a large bowl, toss roasted cauliflower, corn, onion and arugula; set aside.

In a small bowl, whisk vinegar, lemon juice, lemon zest, sea salt, pepper and remaining 2 Tbsp. olive oil; drizzle over cauliflower mixture. Transfer to serving bowl; garnish with pepitas and serve warm or at room temperature.