2 lbs beef chuck cut into cubes

2 tablespoons olive oil

2 tablespoons unsalted butter

1 large onion finely chopped

3 cloves garlic minced

3 large carrots peeled and chopped

3 medium potatoes peeled and cubed

2 celery stalks sliced

2 tablespoons tomato paste

2 tablespoons all-purpose flour

11.2 oz Guinness stout

3 cups beef broth

1 tablespoon Worcestershire sauce

1 teaspoon dried thyme

1 teaspoon dried rosemary

2 bay leaves

1 teaspoon salt

1/2 teaspoon black pepper

1 teaspoon sugar optional

2 tablespoons fresh parsley chopped