Pre-Heat the Oven to 200 Degrees Celsius, with the top grill turned on.
Remove skin of Sweet Potatoes and Parsley Root, wash all vegetables and the Rosemary branch.
Cut Onions into small cubes. Cut Mushrooms, Fennel, Garlic, Sweet Potatoes, Carrots and Parsley root into thin slices. Cut Savoy leaves in bigger squares.
Add half of the Olive Oil into a large pan, soften the onions. Turn up heat and add first the Sweet Potatoes. After 3-4 minutes, add Carrots, Garlic, Mushrooms, Parsley Root and Rosemary cut into 4 pieces and roast for 4 minutes. Add salt and pepper as wished. Stir a couple of times. Add Savoy at the end and keep in the pan for 2 additional minutes.
Add the roasted vegetables to a casserole dish and pour the rest of the olive oil over it. Then put in the oven´s upper shelf, close to the roasting grill.
Clean the pan and heat to max temperature.
Prepare the meat by using a drip of olive oil on one side, only put pepper on the side.
Once pan is heated, put the steaks into the pan on the spiced side. Before turning the meat, put a drip of olive oil on the other side and again spice with pepper. The meat can be prepared as wished, I prefer medium rare, which is 2-3 minutes roasting each side.
Turn temperature of the oven down to 100 Degrees Celsius. Keep the vegetables in the upper shelf.
Wrap each roasted piece of meat into aluminum foil, resting it in the lower oven at around 100 degrees Celsius for 10 minutes.
Take out meat and cut as wished, or serve as whole. Serve with the vegetables.