Heat oil with butter. Add chicken and brown on all sides. Salt and pepper the chicken and saute for 1 more minutes. Remove and set aside. Bring sake to a boil. Add shallot and cook for 2 minutes. Add endive to the chicken pan, sprinkle with sugar and brown on all sides. Add chicken, vinegar, soy sauce, garlic and thyme. Simmer for 1 minute. Add sake with the shallots. Bring to a boil, simmer for 20 minutes. Serve on a bed of rice sprinkled wasabi powder.