Prepare pastry. Roll out half of pastry and line a 9-inch pie plate. Preheat oven to 420 degrees.
For filling, toss together sugar, flour, cinnamon, nutmeg, lemon peel and salt with rhubarb and strawberries. Place filling in piecrust; dot with butter.
Roll out remaining pastry for top crus; cut a few slashes and cover filling with slashed top crust: make a decorative edge. Place on a try to catch dripping and bake 50 minutes or until the piecrust is golden brown and filling is bubbly.