This spiced cauliflower and potato recipe cooks in one pan, making it a hassle-free weeknight side dish. Start by browning diced potatoes, then add mustard seeds, ginger, garlic, and spices and cook until fragrant. Add cauliflower and steam until tender. To finish, stir in a pat of butter to melt all over the vegetables. This assertively spiced dish can be served over steamed rice for a hearty vegetarian meal, or next to a simple roasted chicken for dinner.