Preheat oven to 425 degrees.
Prep a baking sheet with baking spray.
Add the melted butter in a large bowl.
In the large bowl combine the carrots, potatoes, and onions.
Stir to mix the vegetables. Season with marjoram, chervil, minced garlic, salt and pepper. Toss.
Spread the vegetables on the baking sheet. Cover with foil.
Bake at 425 degrees for 45 minutes.
Uncover the baking pan. Stir well.
Return to the oven for an additional 30 minutes.
Stir every 10 minutes to move the vegetables from the bottom of the baking dish to the top of the baking dish.
Check to make sure the vegetables are cooked.
Allow the vegetables to brown and become crisp.