Step 1Heat the oven to 350 degrees. Soak the ancho chiles in a bowl of boiling water until softened, about 15 minutes. Drain the chiles, squeezing out any excess moisture, and remove the stems.
Step 2Meanwhile, place one chicken breast on a work surface between two pieces of plastic wrap and, using a mallet or heavy saucepan, carefully pound it to a one-fourth-inch thickness. Work carefully so the chicken doesn't tear and you get a uniform thickness. Sprinkle one-fourth teaspoon salt over the pounded meat. Repeat for the remaining three chicken breasts; wrap them in the plastic and reserve at room temperature while you make the filling.
Step 3In a large skillet over medium-high heat, toast the pepitas, shaking the pan frequently as they pop and turn golden brown, about 5 minutes. Remove from the heat and reserve, setting aside 1 tablespoon of the toasted pepitas to use as a garnish.
Step 4In the same skillet, cook the onions and garlic in 2 tablespoons of the olive oil over medium heat until fragrant and beginning to color, about 4 minutes. Add the chard, allspice, cinnamon, black pepper and remaining one-half teaspoon salt. Continue cooking until the chard has completely wilted, about 4 more minutes. Remove from the heat, but keep the pan on the stove.
Step 5In the bowl of a food processor or blender, blend the toasted pepitas with the anchos, chipotles and a little of the ancho soaking water to form a rough paste, rather like pesto. Add the paste to the pan with the chard mixture and stir to combine.
Step 6Place the chicken breasts on a work surface, remove the top piece of plastic wrap and divide the chard mixture evenly among the chicken breasts. Spread the filling on top to within about an inch of the edges and, one at a time and working from the top of the narrower side, roll the chicken around the filling to make a roulade. Repeat with the three other breasts, being careful to keep the filling encased by the chicken and discarding the plastic wrap.
Step 7Tie the end of a long piece of kitchen twine around the roulade near one end, knotting it at the top. Continue wrapping, making about 5 or 6 turns and making sure that the roulade is compact and fairly tight. Knot at the end and trim the ends of the string. Repeat for each roulade.
Step 8Heat the remaining 2 tablespoons of olive oil in a large oven-proof skillet over medium-high heat. Place all the roulades in the pan and sear them until golden brown, turning them as they cook so they're evenly colored. Place the pan in the oven and roast until the meat is firm throughout and a thermometer inserted reads 165 degrees, about 25 minutes.
Step 9While the chicken is roasting, cook the bacon in a large skillet over medium-low heat until the fat is rendered and the bacon is crisp, about 5 minutes. Add the drained hominy to the pan with the bacon and cook until the hominy is warmed through, stirring frequently. Remove from the heat and add the lime juice and zest.
Step 10Slice the roulades, still tied, into medallions. Remove the twine and serve on a bed of the warm hominy. Garnish with the remaining pepitas and, if desired, cilantro.