Spread the cauliflower florets in a single layer on a baking sheet. Drizzle with olive oil and season with salt and pepper. Roast the cauliflower in the oven for 20-25 minutes, or until it is tender and lightly browned.
While the cauliflower is roasting, make the parsley pesto. In a mortar of food processor, combine the chopped parsley, pine nuts, garlic, olive oil, lemon juice, and salt and pepper to taste. Blend until the pesto is smooth and well combined.
Once the cauliflower is done roasting, transfer it to aserving plate. Top it with peas, pesto sauce, vegan feta cheese, chili flakes and some more chopped parsley.