For the dough, place the flour in a big mixing bowl, then make a hollow in the center. Sprinkle the yeast into the ghollow, then drizzle in the warm water. Mix together, then add 1/2 tsp of the salt and 2 tbsp of the olive oil. Transfer to a lightly floured surface and knead until the dough is smooth and no longer sticky, about 5 minutes. Cover with a clean dish cloth and set aside.
Preheat the oven to 450˚F. Arrange the pumpkin on a baking sheet and top with the remaining tbsp. of olive oil, the garlic, and a sprinkling of salt. Stir to coat with oil. Roast until soft, stirring occasionally, 25-30 minutes. Set aside and allow to cool for a few minutes. Purée in a food procesor until smooth.
Divide the dough into four equal pieces. Shape each piece into a ball. Use a rolling pin to roll each ball out very thinly. Dollop a fourth of the pumpkin purée onto each round, then top with some feta, oregano, and pine nuts. Moisten the dough edges with a bit of water, then join the edges into a rough triangle shape.
Place a sheet of parchment onto a baking sheet, then arrange the fatayer on the baking sheet. Bake until golden brown, 10-15 minutes. Allow to cool for a few minutes before serving.