Heat oil in a large skillet over medium-high heat
Add the sunchokes, 1/4 cup of water, season with salt & pepper
Cover, and stir occasionally until sunchokes are fork-tender, about 8-10 minutes
Uncover skillet, and stirring occasionally, cook until water is evaporated and sunchokes begin to brown and crisp, another 8-10 minutes
Transfer to a platter
Add rosemary and butter to skillet and cook, stirring often, until butter foams then browns, about 4 minutes
Remove skillet from heat and add vinegar, scrapping up any brown bits
Spoon brown butter sauce and rosemary over sunchokes