Slow cooker roast

1 1/2 tablespoons olive oil, divided

1 chuck roast (1.5kg)

Salt and freshly ground black pepper

1 medium yellow onion, peeled, halved and thickly sliced

5 garlic cloves, chopped (1 1/2 tbsp.)

1 1/4 cup beef broth

2 teaspoons Worcestershire sauce

1 tablespoon chopped fresh thyme

1 tablespoon chopped fresh rosemary

2.5 lbs small Yukon gold potatoes, left whole

5 medium carrots (about 450g), peeled and cut into 1-inch pieces*

2 1/2 tablespoons cornstarch mixed with 3 tablespoons beef broth, optional, to thicken the sauce

2 tablespoons chopped fresh parsley

Instructions :