For the salsa: In a small saucepot, bring 2 cups of water to a boil.
In a cast iron skillet, toast the chiles until they start to smoke and blister. Remove from the pan and place in a bowl and cover with boiling water.
In the same cast iron skillet, toast the tomatillo, onion, and garlic until soft and they char a little.
Put the soaked chiles, peanuts, onion, tomatillo, and garlic in a food processor with the chile water. Puree until smooth, and season with salt and pepper.
For the carnitas: In a large stockpot, heat 2 1/2 cups of water with the thyme, oregano, white onion, garlic, and salt. When it comes to a boil add the diced pork butt and cook covered for 1 hour. Remove and drain.
In a large Dutch oven, heat the lard. When lard is smoking, sear the pork to brown all sides. Remove and serve with warm tortillas, guajillo-peanut sauce, radishes, and shredded lettuce.