1. Put pork in a 5- to 6-qt. pan with 3 qts. water; bring to a boil over high heat. Reduce heat; simmer, covered, until meat is tender when pierced, about 2 hours. Drain and reserve broth; skim off fat. Let meat stand until cool; tear into chunks, discarding fat. Return meat to pan.
2. Meanwhile, discard stems and seeds from all the dried chiles, then rinse well. Put in a 3- to 4-qt. pan with 1 qt. water and bring to a boil over high heat. Cover, reduce heat, and simmer, stirring often, until chiles are soft when pressed, 20 to 25 minutes. Drain, reserving 2 cups liquid. In a blender, purée chiles with liquid until very smooth; set aside.
3. In a 1- to 2-qt. pan over medium heat, cook flour, stirring, until deep tan, 5 to 6 minutes; pour into a bowl. When pork is cooked, stir 1/2 cup reserved broth into flour; scrape into pan with meat.
4. In a blender, whirl garlic, coriander seeds, oregano, cumin, and 1 1/2 cups reserved broth until seasonings are very finely ground. Pour through a fine-mesh strainer into pan with meat, pushing on solids to extract as much liquid as possible. Discard seasonings.
5. To meat add 1 1/2 cups chile purée, the tomato, onion, bell pepper, Anaheim chiles, 1/4 cup lard, the bouillon, and garlic salt. Bring to a simmer over medium-high heat, stirring. Cook, stirring often, for 10 minutes to blend flavors. Stir in cilantro and green onions. With a fork, break any meat chunks into shreds.
6. Prepare masa: In a large bowl, break up masa with your hands. Add baking powder and salt; mix well. Heat remaining 2 3/4 cups lard in a 2- to 3-qt. pan over medium-high heat until melted; let stand until cool enough to touch. Pour into masa, add remaining chile purée, and mix with your hands or a heavy spoon. Mix masa vigorously with a spoon (or beat half at a time in a stand mixer) until very smooth and no lumps of masa remain.
7. Peel potatoes and cut into 48 sticks, each 4 to 5 in. long and 1/4 to 1/3 in. thick (save scraps for other uses). Put sticks in a 3- to 4-qt. pan with water to cover. Bring to a boil over high heat; reduce heat and simmer, covered, until tender-crisp, about 3 minutes. Drain and set aside.
8. Separate cornhusks and discard any silks. Select 5 1/2 dozen large outer husks (5 to 6 in. wide across middle and 7 to 8 in. long; trim larger husks to this size). Soak husks in a sink with hot water to cover until they are pliable, about 20 minutes. Rinse, removing any grit; drain and put in a large bowl. Tear about 12 of the husks into long, thin strips. (If assembly takes more than a few hours and husks dry out, briefly resoak.)
9. Assemble tamales: On a large work surface, arrange masa and whole husks at one end, followed by fillings (meat, potatoes, olives, and jalapeños) and husk strips, leaving some space at the other end for tying and stacking tamales.
10. For each tamale, lay a husk fairly flat with smooth side up. Spoon 1/4 cup masa in center. Hold husk with one hand; using quick flicks of back of a soup spoon or a small spatula, evenly spread half of masa from center to one long edge (leave a 1-in. border bare at edge of husk). Repeat on other half of husk, again leaving a 1-in. border bare at edge. Spread 2 to 3 tbsp. meat filling in a band 1 in. from one long edge of masa. Place a potato piece, 2 olives, and a jalapeño piece over meat. Fold long edge of husk closest to fillings over them, then roll up snugly. If husk doesn't quite meet to enclose filling, patch with a piece of another husk. Using husk strips, tie tamale as tightly as possible at both ends, then just to hold in center. (If needed, knot two strips together to make a longer tie.) Repeat to make remaining tamales.
11. To steam 2 dozen tamales, set a rack on supports at least 1 1/2 in. above bottom of an 8- to 10-qt. pot. Fill pot with 1 in. reserved pork broth or water. Arrange first layer of tamales in one direction on rack; change direction of tamales 90° with each additional layer.
12. Cover and bring to a boil over high heat, then simmer until masa no longer sticks to husks, 1 to 1 1/4 hours, occasionally adding boiling water to maintain level of liquid. Serve with salsa.
Quick Tips: Find dried chiles, cornhusks, and fresh masa at a Mexican market or well-stocked grocery store. You can also buy fresh masa from a tortilla company.
Make ahead: Pork, through step 5, up to 2 days, chilled. Masa (step 6), up to 4 hours, covered at room temperature; up to 2 days, chilled (bring to room temperature before using, 4 to 5 hours). Uncooked tamales can be frozen up to 2 months; no need to thaw before cooking, but increase steaming time to 1 1/2 to 1 3/4 hours.
Note: Time 6 hours (with 3 people helping to assemble); nutritional analysis is per tamale.