Combine the cauliflower and 2 tablespoons of the olive oil in a medium bowl. Heavily season with salt and pepper. Add the oregano and toss to combine. Spread the cauliflower evenly on a baking sheet. Bake until the cauliflower is caramelized and golden in color, about 40 minutes. Let cool.
In a small mixing bowl, mix the pepperoncini, pickling juice and remaining 1 tablespoon olive oil. Season with salt. Mix well until evenly incorporated.
Toss the pepperoncini mixture, Parmesan, jalapenos and pine nuts with the roasted cauliflower. Garnish with the parsley and serve.