Heat your oven to 400°F (200°C).
Chop your purple cauliflower roughly into florets and toss them in a roasting pan with 2 tablespoons of olive oil and the salt, black pepper, and red pepper flakes. If roasting your garlic, drizzle the cloves with a bit of oil and wrap them in foil.
1 medium head of purple cauliflower, 3 tablespoons olive oil, ½ teaspoon salt, ¼ teaspoon black pepper, ⅛ teaspoon dried red pepper flakes, 2 cloves garlic
Roast in the preheated oven for 30 to 40 minutes until the cauliflower can be easily pierced with a fork and slightly caramelized, and the garlic is soft. Stir or shake the pan when you are halfway through cooking to ensure even roasting. Let cool.
Blend the cauliflower dip In a food processor by combining the roasted purple cauliflower, peeled garlic, and crumbled feta cheese. Add the remaining tablespoon of olive oil and blend until smooth. If you prefer a tangy flavor, add 1 to 2 tablespoons of lemon juice, a little at a time, and blend again.
½ cup (2 ounces) crumbled feta, 1 to 2 tablespoons lemon juice, 3 tablespoons olive oil
Taste and adjust with more salt and pepper if needed. Transfer the cauliflower dip to a serving bowl and drizzle with a bit more olive oil if desired.
Store your purple dip in an air-tight container in the refrigerator for three to five days.