Salt and pepper the roast.
In a large stock pot warm the olive oil over medium-high heat.
Place the roast in the oil and brown on all sides.
In a medium bowl combine the tomato sauce, water, spaghetti seasoning, mushrooms, and garlic. Pour over the pot roast.
Cover tightly. Place in a 350°F oven and bake 3 - 3½ hours, or until tender.