If using, cook Dr. Praeger's All American Veggie Burgers according to package directions.
Preheat oven to 400F. Line a baking sheet with parchment paper.
Add all of the veggies to a large mixing bowl. Drizzle with the olive oil and a pinch of salt and pepper. Toss to coat. Transfer to the baking sheet and arrange in an even layer.
Lay the rosemary sprigs across the sheet, and roast for 25-30 minutes, until the veggies are fork-tender and lightly caramelized.
If using, slice each veggie burger into pieces, and arrange on the sheet pan.