Mix dry ingredients. Cut in shortening or room temperature butter until mixture forms pee size clumps.
From dough into ball and roll out to a 1/8" thick rectangle on floured surface. Line 13" x 9", deep dish pyrex.
Beat eggs, sugar, lemon rinds, orange rinds with a mixer until there are no lumps.
Gradually add ricotta while mixing on lowest speed.
!!!WARNING DO NOT OVER MIX!!!
Bake at 375˚ for 45 to 60 minutes until crust is golden brown.