Season the pork chops with kosher salt and pepper and let sit at room temperature for 30 minutes. Preheat a grill and brush the grate with oil.
Meanwhile, in a medium saucepan, cover the potatoes with cold water and bring to a boil. Season the water with kosher salt. Cook until the potatoes are just tender, 12 to 15 minutes, then drain them and let cool slightly. Skewer the potatoes, leaving a few inches on each end for easy handling.
Grill the pork chops over moderately high heat, covered and turning once, until browned and an instant-read thermometer inserted in the thickest part registers 140 degrees, about six to seven minutes per side.
Pile the rosemary and sage on a cutting board. Place the pork chops on the bed of herbs, arranging a few sprigs on top of the meat, and let rest for 10 minutes.
Meanwhile, grill the broccoli and and potatoes on high heat, turning, until tender and charred on the outside, about 10 minutes. Grill the lemon cut side down until charred, about five to seven minutes.
To serve, arrange the pork chops and grilled vegetables on a platter and garnish with a squeeze of grilled lemon. Drizzle with olive oil and sprinkle with flaky sea salt.