Preheat your oven to 400°F (200°C).
Whisk the balsamic vinegar, olive oil, minced garlic, thyme, salt, and pepper in a large bowl.
Place the diced beetroot in a baking dish and toss with half of the balsamic mixture.
Roast the beetroots in the oven for 30-40 minutes or until tender and caramelized, stirring occasionally.
While the beetroots are roasting, season the beef tenderloin with salt and pepper.
Heat a large skillet over medium-high heat and sear the beef on all sides until a brown crust forms, approximately 2 minutes per side.
Transfer the seared beef to a roasting pan and brush with the remaining balsamic mixture.
Place the beef in the oven and roast alongside the beetroot for 20-25 minutes for medium-rare or until desired doneness is reached.
Remove the beef from the oven and let it rest for 10 minutes before slicing.
Serve the sliced beef with the roasted beetroot and drizzle with any balsamic juices from the roasting pan.
Garnish with fresh parsley before serving.
Prep: 20 minutes
Cook: 1 hour
Total: 1 hour 20 minutes
Servings: 6Cooking Time: 1 hourTotal Time: 1 hour 20 minutesKcal: 650 per serving