Rosemary Pork with Balsamic Spinach and Potatoes

• boneless pork loinpatted dry1 lb
• yukon gold potatocut into 1-inch cubes1 3/8 lb
• frozen spinach:null6 oz
• onionthinly sliced1/3 lb
• cooking oil:null8 tsp
• dried rosemary:null1/2 tsp
• balsamic vinegar:null4 tsp
• kosher salt:null,1 tsp
• black pepper:null1/2 tsp

Instructions

1. 1Cut the potato into 1-inch cubes and thinly slice the onion. Do not rinse the pork; pat it dry, then season it on all sides with salt, pepper, and rosemary.
2. 2Heat half the cooking oil in a skillet over medium heat. Add the potatoes and onion, season lightly with salt, and cook for 10-12 minutes, turning occasionally, until the potatoes are fork-tender and golden brown.
3. 3Push the vegetables aside, add the remaining oil, and sear the pork for 4-5 minutes per side, until browned and the thickest part reads 145°F (63°C). Transfer it to a plate and let it rest at least 3 minutes before slicing.
4. 4Wash the board, knife, and hands with soap and water before handling anything else. Add the spinach to the skillet and cook for 3-4 minutes, stirring, until hot and wilted. Stir in the balsamic vinegar, taste, and adjust seasoning; serve with the sliced pork and potatoes.