Strip the kale leaves from tough stems; discard stems. Toss leaves on a rimmed baking sheet, with 2 tbsp. of the olive oil and ¼ tsp. salt, and spread in even layer. Broil greens, stirring once or twice until they turn a brighter green with bits of charred leaves; about 4 minutes. Stir in walnuts and broil until walnuts are fragrant but not burned, about 2 minutes. Set aside to cool.
Sprinkle both sides of chops with ½ tsp. salt, ¼ tsp. pepper and the rosemary. Heat 2 tbsp. of the olive oil in a large skillet over medium heat and cook chops, turning once, until an instant-read thermometer inserted into the thickest part registers 145ºF, about 12 minutes. Transfer to a cutting board to rest for 5 minutes.
While the chops are cooking, pulse garlic and cooled kale and walnuts in a food processor until chopped. Add the pepper flakes, lemon juice, ¼ tsp. salt and the remaining ½ cup olive oil and continue to process to make a slightly chunky pesto. Adjust the consistency as desired with up to ¼ cup water. Season to taste with salt and pepper. Top each pork chop with about 2 tbsp. of the pesto and serve with a side salad.