Preheat oven to 400°F. Coat a large rimmed baking sheet with cooking spray.

In a large bowl combine 5 cups chopped fresh broccoli, 1 1/2 tablespoons olive oil, 2 tablespoons mayonnaise, 1/2 tablespoon lemon juice, 2 teaspoons Sriracha sauce, 1/4 teaspoon salt, and 1/4 teaspoon black pepper.

Toss everything until the broccoli is evenly coated.

Spread the broccoli in a single layer on the prepared baking sheet (avoid crowding so pieces roast instead of steam).

Roast in the preheated oven for 10 minutes. Remove the pan, stir or flip the broccoli pieces, then return to the oven and roast an additional 5–10 minutes, until edges are browned and broccoli is tender.

Remove from oven and serve.