Preheat oven to 425°F.
Trim the large leaves and any long pieces of the stem from the broccoli and cauliflower. Cut them into two to three inch pieces.
Place all the chopped broccoli and cauliflower in a large bowl or pot and drizzle with olive oil and salt and pepper. Use your hands to toss the vegetables with the olive oil; they should be lightly coated, but not drenched in oil.
Spread them into large glass baking dishes or rimmed cookie sheets, spreading into a single layer (if they are piled on top of each other, they will steam instead of roast). Roast for 20 – 30 minutes, although you should begin checking them after 15 minutes when you may want to toss them again to avoid letting the bottoms burn. They should be taken out when they start to brown in spots and are just becoming tender. This dish is delicious when paired with a spiced yogurt dipping sauce.
For Spiced Yogurt Dipping Sauce
Mix all ingredients together