Clean and core the cauliflower. Blanch in boiling water for 3 minutes, then roast at 350F uncovered for 35 minutes, or until it's golden and just tender if you poke it with a knife. To make the salsa verde, blend the first 4 ingredients together until it's a pasty consistency; whisk in the oil. Whisk together all the ingredients for the lemon yogurt.
To toast the pepitas, toss in olive oil and salt. Roast at 350?F for 10 minutes, or until toasted. To serve, top the roasted cauliflower with salsa verde, lemon yogurt and pepitas. Serves 6-8.