Steam cauliflower and potatoes until easily poked through with a knife or fork (about 10 minutes).

Drain and save cooking water. Remove the steamer basket, or transfer the potatoes and cauliflower to a new pot or large bowl.

Add roasted garlic*, onion powder, and half of the parsley to the cauliflower and potatoes.

Using an electric mixer (or handheld masher, if you prefer chunkier mashed potatoes), begin to blend the ingredients together. Add in some of the saved cooking water little by little, as needed. *vegetable broth can also be used - see notes.

When desired consistency is reached, stir in chives and remaining parsley. Top with freshly ground black pepper, if desired.