In a large skillet, heat the olive oil on medium-high heat. Add the sunchokes and sprinkle with coarse salt and pepper. Sauté until tender and brown on both sides, about 5 minutes per side. Place the sunchokes on a serving plate.
Add the butter and lemon juice to the skillet and cook until the butter starts to brown a bit, about 1 minute (be careful not to burn!). Pour the butter/lemon juice over the sunchokes and sprinkle with parsley.