Slow Cooker Beef Stew

lbs chuck roast, (trimmed of excess fat and diced into 1-1/2 inch cubes (you should have about 2 lbs once trimmed))

olive oil

Salt and freshly ground black pepper

large yellow onion, (chopped (1 1/2 cups))

medium celery stalks, (chopped (1 1/4 cups))

garlic, (minced (1 1/2 Tbsp))

tomato paste

low-sodium beef broth or chicken broth, (divided)

Worcestershire sauce

low-sodium soy sauce

minced fresh thyme ((or 1 tsp dried))

(7-inch) single sprig rosemary ((or 3/4 tsp dried))

lbs yellow potatoes, (diced into 1 1/2-inch chunks)

carrots, (peeled and cut into 1-inch chunks (don't use thin carrots))

cornstarch ((depending on how thick you like it))

frozen petite peas

minced fresh parsley