To make the pastry: Combine flour, turmeric, and salt in a large bowl and mix well. Add the butter to the flour mixture and mix ingredients with two knives until it resembles sand or pulse ingredients in a food processor. Combine the vinegar and water. Add the vinegar mixture to the pastry mixture one tablespoon at a time while mixing and being careful not to overwork the dough. The consistency is right when the dough comes away from the sides of the bowl. Form the dough into a ball, flatten, cover in plastic wrap, and refrigerate for 30 minutes to an hour.
To make the filling: In a medium-sized pan, over medium-low heat, heat the oil. Add the onion, Scotch Bonnet pepper, garlic, and salt. Cook while stirring occasionally for about 5 minutes, being careful not to scorch the garlic. Add the garlic powder, thyme, curry powder, allspice, and pepper. Cook for a minute or two until the spices are fragrant. Turn up the heat to medium and add the vegan ground meat. Break it up as you sauté for 8 to 10 minutes until it's fully cooked. Taste and adjust seasonings if desired.
Preheat oven to 375ºF. Remove dough from the refrigerator. Line a baking tray with parchment paper. Lightly dust the work surface with flour and roll out the dough until it's about 1/8-inch thick. Cut dough into 4 to 5-inch circles using a cookie-cutter or thin-rimmed glass. Reroll scraps and cut again. Spoon filling onto one side of each circle, leaving about 1/8 inch border to seal. Wet fingers with water and run around the edge of the dough before folding and sealing each one with your fingers or a fork. Transfer patties to the parchment-lined baking sheet and bake for about 30 minutes or until pastry is lightly browned on the bottom. Serve immediately.