Heat oil in skillet. Season liver with and pepper. Coat both sides of liver with flour. When oil is heated, fry liver until browned on both sides. Remove liver, set aside.
Add onions and peppers, saute until tender. Remove onion mixture.
Combine water and cornstarch, stir to dissolve cornstarch, add to skillet. Bring to a boil, if the mixture becomes too thick, add more water to pan. Re-season water, if needed. Add kitchen bouquet to desired color.
Add liver back to pan, put onion mixture on top of liver. Simmer for 20 minutes.