Rhubarb nectarine pie

Joy of Cooking's "basic pie dough"
Sift together:
2 c. all-purpose flour
1 tsp salt
2 T brown sugar (my addition)
Measure and combine:
2/3 c. shortening
2 T butter
Work the dough together and add
4 T water
Mix it until you can pat the dough into a big ball. Add a tiny bit of water (<1T) if necessary. Don't overhandle the dough.
Divide dough in two parts, and roll out a top and bottom crust.

Pie Filling (my invention)
2 c. chopped rhubarb
3 c. diced nectarines with the skins still on
2/3 c. brown sugar
2 T cornstarch

Pour fruit into bottom crust. Cut up 1-2 T butter and scatter the pieces around in the fruit. Wet the edge of the bottom crust and put the top crust over it. Use a fork to squish the two crusts together. Poke holes in the top of the pie. Glaze it with a little cream. Sprinkle a bit of brown sugar over the top. Bake 10 minutes at 450º, then lower the heat to 350º and bake 40 more minutes.