Squeeze juice from lemon into bowl of ice water; add lemon halves and artichoke hearts while preparing the rest.
In a large skillet over medium heat, add oil, garlic, and salt. Stir in red-pepper flakes, parsley, basil, salt, and black pepper, and saute, stirring for 5 minutes. Add vermouth, and cook for 2 minutes. Add tomato sauce and chicken stock. Cook until slightly reduced, about 5 minutes.