To prepare the empanada filling, preheat the oven to 350°F.

In a large bowl, stir together the pork, garlic powder, onion powder, chili powder, cumin, paprika, salt and pepper. 

In a large sauté pan over medium-high heat, working in batches if needed, sear the pork. Transfer to a large baking dish. In the same pan, cook the onion, stirring occasionally, until softened. Place the onion on top of the pork. Add the broth to the baking dish. 

Cover the dish, transfer to the oven and cook until the meat is tender, about 1 1/2 hours. Let the pork mixture cool slightly and then mix with the onion, cilantro, green onions and oregano. Add more of the spice mix, if desired. 

Cover and refrigerate the pork mixture overnight before filling the empanadas.

To prepare the romesco sauce, stick a fork through the cascabel peppers and place them, tines-down, in a bowl (to keep the peppers submerged). Cover with boiling water and let stand until softened, at least 30 minutes. Remove the stems and seeds from the peppers and set aside.

Meanwhile, roast the bell pepper on a gas stovetop directly over a flame or on a sheet pan under the broiler. Place the peppers in a plastic bag or in a bowl and cover with plastic wrap; let cool. Peel the peppers and remove the stem and seeds (don't rinse the pepper); set aside.

Position a rack in the upper third of the oven and preheat the oven to 375°F. 

Spread the hazelnuts and almonds out on separate baking sheets in a single layer. Toast in the oven until golden and aromatic, 8 to 10 minutes. If the hazelnuts have skins, let them cool, then roll them in a kitchen towel to remove the skins. Set aside the nuts and increase the oven temperature to broil.

Line a baking sheet with aluminum foil. Place the tomatoes, cut side down, on the prepared baking sheet and coat with 1 tablespoon of the olive oil. Broil the tomatoes until the skins begin to darken and crack, about 5 minutes. Let the tomatoes cool on the baking sheet, then peel, core and set aside.

In a large fry pan, warm the 1 tablespoon of the olive oil. Add the bread and fry, turning once, until golden brown. Transfer to a plate and let cool.

In a food processor, combine the garlic, salt, fried bread, hazelnuts and almonds and coarsely chop. Add the cascabel peppers and bell pepper, tomatoes, paprika, vinegar and parsley and process until a rough paste forms. Slowly pour in the 1/4 cup olive oil in a steady stream and process until combined.

Preheat the oven to 350°F.

To assemble, choose your favorite savory dough. Roll out the dough and cut circles 3 to 3 1/2 inches in diameter.

Place 3 tablespoons of the filling on each dough circle. Moisten the end of the dough, fold it over and seal to form half-moons. Place on a baking sheet.

Bake until the empanadas are golden, about 15 minutes. Serve with the romesco sauce on the side. 

NOTE: You can make the empanadas in advance and freeze them before baking. Remove them from the freezer and bake the frozen empanadas at 325°F for 20 minutes.