In a large skillet heat oil over high heat. When hot add crawfish, green onions, garlic, Creole seasoning and salt; saute 2 minutes. Add heavy cream and cheese, immediately remove from heat and stir well. Fold in bread crumbs, transfer filling mixture to a bowl and let cool 15 minutes.
In a deep-fryer or deep heavy pot, heat oil to 375 degrees F. In a bowl combine masa harina, 1/2 cup of the flour and 1 tablespoon of the Southwest seasoning. Fold in egg whites and add milk a little at a time, mixing thoroughly between additions until all milk is incorporated and batter is smooth. In another bowl combine remaining 1/2 cup flour with remaining 1/2 tablespoon Southwest seasoning.
To prepare peppers, spoon one-quarter of filling into each pepper through slit in side; reform pepper around filling. Dip first in batter then in seasoned flour. When oil is hot (a drop of batter spooned into oil should fry quickly), fry peppers until golden-brown, turning several times, about 3 to 4 minutes. Remove with a slotted spoon and drain on paper towels. To serve, divide salsa among 4 dinner plate and top with peppers; garnish with a dollop of sour cream and a sprig of cilantro.
Yield: 4 servings