Place dried 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软 in a large pot or bucket. Cover completely with very hot water and weigh them down with a heavy plate or bowl. Soak for at least 1 hour, or until fully pliable and soft. Drain, rinse, and pat dry before using. Keep them covered with a damp towel as you work.

Place the 3 磅 猪肩肉 切成 3–4 大块 chunks in a large pot. Add the halved 1 个 白洋葱 切半, smashed 6 瓣 大蒜 拍碎, 2 茶匙 粗盐, and 1 茶匙 黑胡椒粒 整粒. Cover with cold water by about 2 inches. Bring to a boil over high heat, skimming any foam that rises to the surface.

Reduce heat to low, partially cover, and simmer until the 3 磅 猪肩肉 切成 3–4 大块 is very tender and easily shredded with a fork, about 2 to 2.5 hours. Remove the 3 磅 猪肩肉 切成 3–4 大块 and set aside to cool. Strain and RESERVE the 2 杯 猪肉高汤（从煮猪肉时留下） — you will need 5 cups total for the masa and chile sauce. Let the 2 杯 猪肉高汤（从煮猪肉时留下） cool slightly and skim off excess fat.

Once the 3 磅 猪肩肉 切成 3–4 大块 is cool enough to handle, shred it into bite-sized pieces using two forks or your hands, discarding any large pieces of fat or bone. Set the shredded 3 磅 猪肩肉 切成 3–4 大块 aside.

While the 3 磅 猪肩肉 切成 3–4 大块 simmers, toast the 6 个 干瓜希约辣椒 去蒂去籽 and 3 个 干安可辣椒 去蒂去籽 in a dry skillet over medium heat for about 30 seconds per side, pressing them flat, until fragrant and slightly darkened. Do not burn them or the sauce will taste bitter.

Transfer the toasted 6 个 干瓜希约辣椒 去蒂去籽 and 3 个 干安可辣椒 去蒂去籽 to a saucepan. Add enough water to cover and bring to a boil. Remove from heat and let soak for 20 minutes until softened.

Drain the 6 个 干瓜希约辣椒 去蒂去籽 and 3 个 干安可辣椒 去蒂去籽 and transfer them to a blender. Add the 6 瓣 大蒜 拍碎, 1 茶匙 孜然粉, 1 茶匙 干牛至 最好用墨西哥牛至, 2 茶匙 粗盐, and 2 cups of the reserved warm 2 杯 猪肉高汤（从煮猪肉时留下）. Blend on high until completely smooth, about 1–2 minutes. Taste and adjust 2 茶匙 粗盐 as needed. If the sauce seems very thick, add a splash more 2 杯 猪肉高汤（从煮猪肉时留下）.

Heat 1 tbsp of 杯 猪油，室温 or 1 cup shortening in a saucepan over medium-high heat. Pour in the blended chile sauce carefully (it will splatter). Fry the sauce, stirring constantly, for 3–4 minutes until it deepens in color and thickens slightly. This step removes the raw chile flavor.

Add the shredded 3 磅 猪肩肉 切成 3–4 大块 to the red chile sauce and stir to coat thoroughly. The filling should be moist but not soupy. Taste and adjust seasoning. Set aside to cool slightly.

In the bowl of a stand mixer fitted with the paddle attachment (or a large mixing bowl with a hand mixer), beat the 1 杯 猪油，室温 on medium-high speed until light and fluffy, about 3–4 minutes. This step is key to a light, airy masa — don't skip it.

In a separate large mixing bowl, whisk together the 4 杯 玉米粉 如 Maseca 牌, 2 茶匙 粗盐, and 1 ½ 茶匙 发酵粉. Gradually add the warm reserved 2 杯 猪肉高汤（从煮猪肉时留下） and mix until a soft dough forms.

Add the masa dough to the whipped 1 杯 猪油，室温 in 3–4 additions, beating on medium speed between each addition until fully combined. The finished masa should be soft, smooth, and spreadable — similar to thick peanut butter. To test: drop a small ball of masa into a glass (Large) of cold water. If it floats, the masa is ready. If it sinks, beat in a little more 1 杯 猪油，室温 and test again.

Set up your assembly station: soaked 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软 (covered with a damp towel), masa, and pork filling. Take one 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软 and lay it flat with the wide end facing you. Using the back of a wooden spoon or a spatula, spread about 3 tbsp of masa onto the center of the husk, leaving a 1-inch border on the sides and a 2-inch border at the narrow (top) end.

Spoon about 2 tbsp of the pork filling down the center of the masa. Do not overfill — it makes folding difficult.

Fold one long side of the 张 干玉米皮 用温水浸泡至少 1 小时至柔软 over the filling so the masa edges meet and enclose the filling. Then fold the other long side over. Finally, fold the narrow (top) end of the husk up and under the tamale. The open bottom end stays open. Place the tamale seam-side down. Repeat with remaining husks, masa, and filling.

Fill a large steamer pot with about 2 inches of water. Line the steamer basket with extra 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软 or a layer of parchment paper. Stand the tamales upright in the steamer, open end up, packing them snugly together so they support each other. If you have gaps, fill them with crumpled aluminum foil or extra 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软.

Cover the tamales with a layer of extra 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软, then place the lid tightly on the pot. Steam over medium heat for 75–90 minutes, checking the water level every 30 minutes and adding more boiling water as needed to prevent the pot from running dry.

The tamales are done when the masa pulls away cleanly from the 40 张 干玉米皮 用温水浸泡至少 1 小时至柔软. Remove one tamale, let it rest for 5 minutes, then open it to test. If the masa is still sticky or wet, re-cover and steam for another 15 minutes. Let all tamales rest for 5–10 minutes before serving — they firm up as they cool slightly.