Make the carnitas: Melt lard in an 8-qt. saucepan over medium-high. Season pork with salt; cook, turning as needed, until browned, 10–12 minutes. Add milk, garlic, jalapeños and pickling liquid, onion, and lime and orange juices; boil. Reduce heat to medium-low; cook, covered, until pork is tender, about 2 hours. Let pork cool and transfer to a cutting board; chop into bite-size pieces. Strain cooking liquid and return to pan; stir in pork and keep warm. Make the salsa and serve: Heat a 12″ cast-iron skillet over medium-high; cook tomatillos, garlic, and tomatoes, turning as needed, until blackened all over, 12–15 minutes, and transfer to blender. Add jalapeño and pickling liquid, and salt; purée until smooth. Serve carnitas on tortillas with salsa; garnish with cilantro and radishes. Serve with more pickled jalapeños and the orange wedges.