Nutritious Roast Dinner Delight

Preheat the Oven:
Preheat your oven to 180°C (160°C fan) or gas mark 4.

Prepare the Potatoes:
Bring a large pan of water to a boil. Add the thickly sliced potatoes and cook for 5 minutes. This will help soften them before roasting. After 5 minutes, drain the potatoes, but make sure to reserve the water for later.

Prepare the Vegetables:
In a large mixing bowl, toss the partially cooked potatoes, halved carrots, quartered red onions, and trimmed Brussels sprouts with 2 tsp of rapeseed oil. Make sure all the vegetables are well-coated in the oil.

Roast the Vegetables:
Spread the coated vegetables out on a non-stick baking sheet, ensuring they are spaced apart for even roasting. Scatter 1 tsp of fresh thyme leaves over the top, and season with freshly ground black pepper. Roast in the preheated oven for 30 minutes.

Marinate the Steak:
While the vegetables are roasting, prepare the marinade for the steak. In a small bowl, mix 1 tsp of balsamic vinegar with the finely grated garlic, the remaining thyme leaves, and the remaining rapeseed oil. Add a generous amount of black pepper to taste. Rub this marinade over the fillet steak, ensuring it's evenly coated. Place the steak in a shallow dish and set aside to marinate.

Prepare the Gravy:
In another bowl, mix the remaining balsamic vinegar with the vegetable bouillon powder and 125ml of the reserved water from the boiled potatoes. Set this mixture aside to use as gravy later.

Turn the Vegetables:
After 30 minutes of roasting, carefully take the baking sheet out of the oven. Use a spatula to turn the vegetables over to ensure even cooking. Return the baking sheet to the oven and roast for an additional 15 minutes.

Cook the Steak:
Heat a small non-stick frying pan over medium-high heat. Remove the steak from the marinade, shaking off any excess. Fry the steak for 2-3 minutes on each side, or until it reaches your desired level of doneness. Once cooked, transfer the steak to a cutting board and let it rest for a few minutes.

Make the Gravy:
Pour the leftover marinade from the frying pan into the pan over medium heat. Let it bubble and reduce slightly until it thickens into a gravy.

Serve:
Once the vegetables are golden and tender, remove them from the oven. Slice the rested steak and arrange it on plates alongside the roasted vegetables. Drizzle the thickened gravy over the steak or serve it on the side. Enjoy your healthy roast dinner!