Step 1: Preheat the Oven

Preheat your oven to 425°F (220°C). This high temperature ensures the veggies get crispy on the outside while staying tender on the inside.

Step 2: Prepare the Vegetables

Wash the broccoli and cauliflower thoroughly. Cut them into evenly sized florets to ensure even cooking. Pat them dry with a clean kitchen towel to remove excess moisture.

Step 3: Season the Veggies

In a large mixing bowl, combine the broccoli and cauliflower florets. Drizzle olive oil over the veggies and toss to coat evenly. Add garlic powder, onion powder, smoked paprika, black pepper, salt, and red chili flakes. Mix well so that every floret is seasoned.

Step 4: Arrange on a Baking Sheet

Line a baking sheet with parchment paper or a silicone mat for easy cleanup. Spread the seasoned broccoli and cauliflower in a single layer, ensuring they’re not overcrowded. This helps them roast evenly and become crispy.

Step 5: Roast in the Oven

Place the baking sheet in the preheated oven and roast for 20-25 minutes, flipping the veggies halfway through. Keep an eye on them to avoid burning. The edges should be golden brown and crispy.

Step 6: Add Finishing Touches

Once roasted, remove the veggies from the oven. Drizzle with lemon juice and sprinkle grated Parmesan cheese (if using) for an extra layer of flavor. Toss gently and serve immediately.