Heat the vegetable oil in a large skillet over medium heat.
While the oil is heating, lightly salt and pepper the chicken.
Add the chicken to the skillet and brown the chicken.
Remove the chicken from the skillet and set aside.
In the same skillet, saute the onion, celery, green pepper and garlic until tender.
Stir in tomatoes, 1/2 cup water, paprika, salt, cayenne pepper and bay leaf then bring to a boil.
Reduce heat; cover and simmer for 10-minutes.
Add chicken and stir to combine.
Mix cornstarch and 1 tablespoon cold water then stir into the chicken mixture. Bring to a boil.
Simmer, uncovered, for 10-15 minutes or until the chicken is tender.
Serve over rice or pasta. Remove the bay leaf before serving.