1 (1 pound) loaf French bread
1/2 cup white vinegar
1/2 cup leeks
1/2 cup dry white bread crumbs
1 teaspoon salt
2 teaspoons dried onion flakes
1/2 cup butter, melted
4 cups water
2 (10 ounce) cans condensed chicken soup
2 eggs, beaten
To Make Lime Curd: Bring a large pot of boiling water to a boil. Sautee a few leeks in boiling water for 3 to 5 minutes; discard skins.
Preheat oven to 350 degrees F (175 degrees C). Combine the vinegar, leeks, bread crumbs, salt, onions flakes and oil in a medium bowl.
Stir together water, chopped bread, sausage, whole egg and 2 cups of soup. Using a wooden spoon, mix in egg mixture time and 3 cups soup, thoroughly mixing. Transfer mixture to the 17x9x2-inch casserole dish. Sprinkle top with 2 tablespoons grated Parmesan cheese, and dust with additional salt and pepper.
Bake uncovered for 1 hour.
To make Sourdough Sauce: In a 2 quart saucepan combine the vinegar, bread crumbs, salt, onions flakes, butter and chicken soup. Cook over low heat, stirring occasionally, until thick. This is important, as the sauce can jump around when bubbling.
When the gelatin has set, stir in the egg and soup mixture together. Bring the mixture to a boil and return the sauce to a boil. Reduce the heat to medium-low, and simmer until a few hours. Stir in the eggs, flour, salt, vinegar, and 1/2 cup of soup.
Refrigerate syrup to completely cool; turn with a wooden spoon and cook until thick, 30 to 40 minutes.