Preheat the Oven: Start by preheating your oven to 400°F (200°C). This ensures that the potatoes will roast evenly.

Prepare the Potatoes: In a large bowl, toss the quartered potatoes with 1 tablespoon of olive oil, salt, pepper, and half of the minced garlic (2 cloves). This simple seasoning enhances the natural flavor of the potatoes. Make sure each potato is coated.

Roast the Potatoes: Spread the potatoes in a single layer on a baking sheet. Roast for 20-25 minutes, or until golden brown and tender. Flipping them halfway through can ensure even browning.

Prepare the Beef Medallions: While the potatoes are roasting, pat the beef medallions dry with paper towels. This is crucial for achieving a good sear. Season generously with salt and pepper. Don't be afraid to season well – this is your chance to build flavor!

Sear the Beef: Heat 1 tablespoon of olive oil and 1 tablespoon of butter in a large oven-safe skillet over medium-high heat. The combination of oil and butter adds flavor and helps create a beautiful crust.

Sear Each Side: Sear the beef medallions for 2-3 minutes per side, until a golden crust forms. Avoid overcrowding the pan, as this will lower the temperature and prevent proper searing. Work in batches if necessary.

Make the Umami Glaze: In a small bowl, whisk together the soy sauce, balsamic vinegar, honey, and Dijon mustard. This umami glaze is the secret ingredient that elevates these beef tenderloin medallions to the next level.

Glaze the Beef: Pour the umami glaze over the seared beef medallions in the skillet. Make sure each medallion is properly coated for maximum flavour!

Bake to Perfection: Transfer the skillet to the preheated oven and bake for another 5-7 minutes, or until the medallions reach your desired level of doneness. Use a meat thermometer to check for doneness. Remember, carryover cooking will continue to raise the temperature slightly after you remove it from the oven.

Rest the Beef: Remove the skillet from the oven and let the medallions rest for a few minutes. This allows the juices to redistribute, resulting in a more tender and flavorful steak.

Make Garlic Herb Butter: While the beef is resting, melt the remaining 1 tablespoon of butter in the same skillet over medium heat. Add the remaining minced garlic, parsley, and thyme. Cook for about 1 minute, until fragrant.

Flavor the Potatoes: Toss the roasted potatoes with the garlic herb butter. Make sure each potato is coated with the fresh herby and garlicky butter sauce!

Serve and Enjoy: Serve the seared beef medallions over the garlic herb potatoes, spooning any remaining umami glaze over the beef.