Heat 1 teaspoon olive oil in a Dutch oven over medium-high heat. Add shallots to pan, and sauté for 3 minutes or until golden. Add garlic to pan; sauté 1 minute. Transfer shallot mixture to a large bowl.
Heat remaining 2 teaspoons olive oil in pan over medium-high heat. Place 1/4 cup flour in a shallow bowl or pie plate. Dredge half of chicken in flour, shaking off excess. Add dredged chicken and 1/8 teaspoon black pepper to pan, and cook for 6 minutes or until browned on all sides. Add browned chicken to shallot mixture. Repeat procedure with remaining flour, chicken, and 1/8 teaspoon black pepper.
Add sake to pan; bring to a boil, scraping pan to loosen browned bits. Add broth, tamari, and 1/2 cup water. Add chicken mixture to pan, stirring to combine. Cover, reduce heat, and simmer for 30 minutes.
Combine remaining 1/2 cup water and 1 tablespoon flour in a small bowl; stir until smooth. Add flour mixture to pan; stir well. Stir in potato. Cover and simmer 15 minutes or until potato is tender. Uncover and simmer 15 minutes or until desired thickness. Remove from heat; stir in parsley.