Add tomato sauce, beef stock, herbs, lentils and water. Stir to combine, and bring to a boil. Stir well, reduce heat to low, cover, and simmer for 20 minutes. Uncover, stir well, and add 1 teaspoon of French Picnic sea salt. Cover again, and cook for 15-20 minutes more, or until lentils and beef are both tender.