Preheat oven to 325°. Melt butter with the oil in a large skillet over medium-high heat. Saute the pork until light brown and transfer to large pot. Add onions and carrots to butter and oil mixture and saute on low heat just until soft. Whisk in the flour, salt and pepper, stirring until smooth and bubbly. Add wine and water and simmer over low heat until mixture begins to thicken. Pour the mixture over the pork along with the parsley. Cover and place in oven for 1 1/2 hours or until the meat is tender.
Arrange celery slices and minced celery leaves over pork. Cover and bake additional 20-30 minutes. In a small bowl, beat egg yolks with a whisk until thick and lemon colored. Slowly beat in the lemon juice. Add a few tablespoons of the hot broth to the egg mixture to heat through. Pour egg mixture into the stew and stir well. Adjust seasoning. Turn heat off and return pot to oven for 5 minutes (uncovered). Serve over rice. 6-8 servings.