To make the pastry, combine the flour, baking powder and salt in a food processor and pulse to combine. With the motor running, add the oil and cottage cheese, then the water. Pat the dough into a disc, wrap in plastic and refrigerate for 30 minutes or up to 3 days.
Preheat oven to 400°F. In a heavy pot, heat the butter over medium-high heat. Add the onion, carrot and celery and cook, stirring often, until softened, about 10 minutes. Add the garlic and cook another minute, then sprinkle in the flour. Stir to coat the vegetables with the flour, then add the white wine. Cook for 1 minute, then add the chicken stock and dill. Bring to a simmer, then season to taste with salt and pepper. Turn off the heat and add the peas. Divide the contents amongst 4 (8-ounce) ramekins or ovenproof bowls. Set aside to cool to room temperature before proceeding.
On a floured surface, roll out the dough to 1/4-inch thickness, then cut into 4 quarters. Place one piece of dough on each filled ramekin. Cut vent holes in the top of the dough. Place on a sheet tray in the oven and bake until mixture is bubbling and pastry is golden, 25–35 minutes. Let cool slightly and serve.