Rub all sides of pork roast with salt and pepper. Heat olive oil over medium heat in a 10 inch skillet until glistening. Sear pork 1-2 minutes on each side.Place roast in slow cooker and sprinkle rosemary, thyme, & garlic on top.Place potatoes, carrots, & onions around roast. Pour in chicken broth & 2 c. water. Liquid should almost cover everything, if not, add more more water.Cook on low 8-10 hours.
Gravy
Remove 3 cups of the broth to a medium sauce pan and bring to a boil. Combine cornstarch to 1 cup warm water and stir.Add to broth and simmer 3-5 minutes stirring constantly until thickened.