To prepare crust:
Cut shortening into dry ingredients and add water. Form ball, chill and roll flat for pie pan.
Preheat oven to 400F. Prick crust with a fork and bake 10 minutes in a 9 or 10 inch pie pan at 400F. Remove from oven and reduce heat to 325F. Remove Italian sausage from casing; cook in skillet until done. Break into small pieces. Cover bottom of crust with two layers of tomatoes.
Sprinkle with oregano, basil, salt and pepper Put a layer of chopped onions and sausage. In a bowl, combine cheese and mayonnaise, mix until well blended and spread half of mixture over meat.
Repeat layering with the remaining tomatoes, oregano, basil, salt and pepper and the other half of the mayonnaise spread.
Top with Parmesan cheese and bake until golden and firm, about 45 minutes at 325F. Cool slightly and cut into slices.
Serves 6 to 8.
Cajun Country -- New Iberia, Louisiana