Spray the inside of the slow cooker with cooking spray. Rinse and pat dry the pot roast. Drizzle with olive oil then rub with steak seasoning, black pepper and minced garlic on all sides. Center in the slow cooker.
Arrange the carrots and onion wedges around the roast, placing a few onion wedges on top. Drizzle the Worcestershire sauce over the roast.
Mix together the coca cola, brown gravy mix and Herbes de Provence until dissolved. Pour over the roast and vegetables. If adding potatoes, arrange the potato halves on top. If serving with mashed potatoes, omit.
Season the vegetables with a light sprinkle of steak seasoning or seasoned salt and black pepper to your taste.
Cook on low for 8-10 hours. To make the gravy, use a slotted spoon to remove the roast and vegetables from the slow cooker to a platter. Cover and keep warm.
Pour the drippings into a saucepan, skimming any excess fat from the top.
Thicken with cornstarch or a flour slurry to make the gravy, if desired.