Preheat oven to 400°., Place butternut squash in a 12-in. cast-iron skillet. Drizzle with oil. Sprinkle with rosemary, thyme, salt and pepper; toss to coat. Roast until just tender, 15-20 minutes. Remove from pan and keep warm., In a large bowl, whisk eggs, milk, flour and cayenne; stir in cheeses. Place butter in same skillet; place skillet in oven until butter is melted, 1-2 minutes. Carefully tilt pan to coat bottom and side with butter. Pour egg mixture into skillet; top with roasted squash., Bake until puffed and edges are browned, 30-35 minutes. Let stand 15 minutes before cutting. Sprinkle with chives and additional Parmesan and Romano cheese blend.