2 sheets puff pastry, frozen
1 tablespoon oil + 1 tablespoon butter
1 sweet, mild onion (Vidalia or Texas Sweet), diced
1 1/4 pounds lean ground sirloin
1/2 teaspoon salt
1/4 teaspoon pepper
2 tablespoons tomato paste
3 tablespoons dark rum
8 slices sharp Cheddar cheese
Preheat oven to 375 degrees F. Line a baking sheet with parchment paper.
Allow puff pastry to thaw for twenty minutes (so it's workable, but still cold). Meanwhile, in a medium skillet, heat oil and butter and saute onion until tender. Add sirloin and mix in with the onions. Cook until lightly browned. Stir in salt, pepper and tomato paste. Add rum and cook until rum reduces. Mixture should be moist, but not drippy.
Place puff pastry sheets on a floured surface and pinch together seams. Prick with a fork all over. Place one sheet on baking sheet and spread beef filling all over, up to the edges. Top with Cheddar cheese and the other pastry sheet.
Bake 20 - 25 minutes or until golden. Let rest a few minutes before cutting it into triangles. Makes 16.