Skin-on, bone-in chicken breasts pack a ton of flavor that gets imparted to the cauliflower that's roasted alongside it.
Preheat oven to 450 degrees. On a rimmed baking sheet, toss cauliflower with 1/2 teaspoon oil. Season chicken with salt and pepper and place, skin side up, in center of cauliflower; roast 20 minutes. In a small bowl, combine 1/2 teaspoon oil, panko, cheese, and rosemary.
Remove sheet from oven. Add beans, lemon zest, and red-pepper flakes to cauliflower; sprinkle cauliflower mixture with panko mixture and roast until panko is golden brown and chicken is cooked through, about 7 minutes.
Use broccoli in place of cauliflower or try chickpeas instead of white beans.