Preheat your oven to 375°F (190°C).
Set heat to medium and cook ground beef in a large skillet until browned. Drain any excess fat.
Add the chopped onion to the skillet and cook until it becomes translucent.
Stir in the shredded cabbage, garlic powder, dried thyme, salt, and black pepper. Cook until cabbage becomes soft.
Remove the skillet from heat and set aside to cool slightly.
Unroll the crescent roll dough and separate it into individual triangles.
Place a spoonful of the beef and cabbage filling onto the wide end of each crescent roll triangle.
Roll up each triangle, starting from the wide end, and tuck in the sides to seal the filling inside.
Arrange the filled crescent rolls on a baking sheet lined with parchment paper or greased lightly.
Optional: Lightly brush the tops of the bierocks with melted butter or beaten egg for a golden finish.
Bake in the preheated oven for 12-15 minutes, or until the crescent rolls are golden brown and cooked through.
Remove from oven. Before serving let them slightly cool.