Make pesto ranch. Combine basil, parmesan, olive oil, lemon juice, and garlic in a food processor or blender. Puree until smooth. Transfer pesto to a bowl and add Greek yogurt, buttermilk, chives, dill, and onion powder. Stir to combine and season with salt and pepper. Let sit for 30 minutes.
Meanwhile, prepare the broccoli. Toss broccoli florets with shallots, olive oil, garlic powder, onion powder, salt, and pepper. Spread broccoli in an even layer on a baking sheet and roast for 25-30 minutes or until tender and charred.
Drain chickpeas and rinse with water. Pat dry with paper towels and place in a food processor. Pulse chickpeas until they resemble small crumbs. Spread in an even layer on a baking sheet lined with parchment paper and season with olive oil, salt, and pepper. Bake in the oven for 25-30 minutes or until browned and crisp, tossing chickpeas halfway through.
Toss broccoli with pesto ranch and transfer to a plate. Sprinkle chickpea breadcrumbs on top, followed by pepitas, parmesan, and sliced pepperoncini. Serve warm or at room temperature.
Notes
You can make the pesto ranch up to 3 days in advance.