11. Place 10-inch cast-iron skillet over high heat. Season hanger steak with salt and pepper. Add canola oil to very hot skillet, and when it is almost smoking (the surface will start to shimmer), sear meat for 4 minutes on each side. 2. Reduce heat to medium-low (letting pan cool down a bit) and add butter and 3 sprigs of thyme. (The pan must cool down before you add the butter or it will sizzle and burn on contact.) Using a spoon, baste steak with butter for 2 to 3 minutes, flipping it once halfway through to cook it evenly. (The temperature for a medium-rare steak is about 135 degrees.) 3. Remove meat from skillet and set aside. Discard all fat and thyme from skillet. (Wipe clean with paper towel.) Over medium heat, cook bacon to render fat and slightly crisp meat, about 5 minutes. Nestle in potatoes (cut-side down if using horizontal version) and cook until crisp and golden, about 4 to 5 minutes. Turn potatoes and continue cooking until crisp tender, another 4 to 5 minutes. 4. Add onion and remaining thyme and cook, stirring occasionally, until onion caramelizes and potatoes are cooked through, 10 to 15 minutes. 5. Lower heat and add garlic, and when you can smell its aroma, add balsamic vinegar and reduce, about 3 minutes.
To serve: Carve hanger steak into 3/4-inch slices and return to skillet, arranging atop vegetables.