1. Preheat oven to 225ºC. Boil potatoes in a large saucepan of salted water for 10 minutes. Remove from heat, drain, run under cold water and carefully remove skin. Drain well and place in a medium bowl; toss with olive oil. Place on a parchment-lined baking sheet.
2. Sprinkle beets with salt and place on a separate parchment-lined baking sheet. Place both baking sheets into the oven and roast for 10 minutes. Turn and shake sheets after 5 minutes.
3. Season steaks with salt and pepper, then grill or fry them to desired doneness. Allow to rest covered loosely with aluminum foil for 5 minutes.
4. In a medium-sized frypan, melt and brown the butter. Add the walnuts and shallot and cook for 2-3 minutes.
5. Remove from heat and add the Castello® Mellow Black and rosemary. Gently stir and allow to slowly melt. Toss the roasted beetroot sticks with the blue cheese dressing and season with salt and pepper.
6. Serve the steaks with roasted potatoes and marinated beets on the side.