Preheat oven to 400ºF.
In a medium saucepan, heat oil over medium; add cabbage and potatoes.
Cook until beginning to brown, 7 to 9 minutes.
Add beef; cook, breaking up meat with a spoon, until no longer pink, about 5 minutes.
Stir in tomato paste, crushed red pepper flakes (if using), Worcestershire, thyme, and 1 cup water.
Cover, and cook until potatoes are tender, about 15 minutes.
Lightly mash mixture with a fork.
Season; salt, & pepper, to taste.
Crushed red pepper flakes, if using (optional)
Let cool completely.
On a lightly floured work surface, roll each crust into a 14-inch square; cut each into 4 equal squares.
Place 1/2 cup filling on one half of each square, leaving a 1/2-inch border around the filling; brush borders with water; fold dough over filling to enclose.
Crimp edges with a fork to seal.
With a paring knife or scissors, cut 3 small vents in each.
Transfer pies to 2 foil-lined rimmed baking sheets; bake until golden brown, 10 to 12 minutes, rotating sheets halfway through.
*Arrange unbaked pies on a baking sheet (they should not touch); freeze until firm, about 1 hour.
Wrap each pie in foil & place in a resealable plastic bag; freeze up to 2 months.
To Bake from Frozen: Proceed increasing baking time to 28 to 30 minutes.