Preheat the oven to 450 degrees F.
Place the grapes on a sheet pan and coat with 2 tablespoons olive oil and season with 1 teaspoon salt and 1/2 teaspoons pepper. Roast until the grapes turn light brown and begin to shrivel, about 45 minutes.
In the meantime, sprinkle the steaks with salt and pepper and let sit for 15 minutes at room temperature.
Heat a pot of water over high heat. Once the water is boiling, add the potatoes, parsnips, bay leaf, 2 sprigs thyme, 1 clove garlic and salt generously. Cook until the vegetables are fork tender, and then strain. Discard the herbs and press the potatoes, parsnips and garlic through a ricer into a saucepan. Gently stir in the cream and season with salt and pepper. Hold warm over low heat.
For the steaks, heat a skillet until very hot, add the remaining 2 tablespoons olive oil and place the steaks in the skillet. Cook about 4 minutes per side for medium-rare. Remove the steaks from the skillet to a plate and tent with foil. Add the red wine to the skillet to deglaze and scrape up any brown bits from the bottom. Add the chicken stock, remaining 1 clove garlic, carrots, onions, celery, the remaining 3 sprigs thyme, the remaining 1 bay leaf and the beef bone. Cook on high heat until the sauce reduces to a syrupy consistency, about 10 minutes. Strain the sauce and add the roasted grapes. Slice the steak off the bone and add the steak juices to the sauce.
To serve, place a spoonful of the parsnips and potatoes on a plate, top with a few pieces of the steak and drizzle with the sauce.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.