Preheat the oven to 350 degrees F. Heat a large heavy skillet over high heat until very hot; add the tomatoes. Cook, turning often, until charred, 2 to 3 minutes. When cool enough to handle, dice the tomato; set aside. Wipe out the skillet and reserve.
In reserved skillet, heat the oil over medium-high. Cook the pork until browned on all sides, about 8 minutes. Remove to a plate. Add the peppers, onion, and garlic to skillet; cook until golden, about 5 minutes. Add the reserved tomatoes and oregano; stir in the broth. Season with salt and sugar to taste. Cook the vegetable mixture until slightly thickened, about 5 minutes.
In a 9 by 13-inch baking dish, place the squash, then top with the onion mixture. Cover the dish with foil and bake until tender, about 20 minutes. Raise the oven temperature to 400 degrees F; uncover the dish and bake until the pork is browned, about 15 minutes. Before serving, sprinkle the stew with pumpkin seeds and serve with tortillas.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.