Here's a simple and delicious recipe for roast beef using a 0.5kg cut:

Ingredients:

• 0.5kg beef roast
• 2 cloves of garlic, minced
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 2 tablespoons olive oil

 Instructions:

1. Preheat the oven to 375°F (190°C).
2. Rub the minced garlic, salt, and black pepper all over the beef roast.
3. Heat the olive oil in an oven-safe skillet or roasting pan over medium-high heat.
4. Add the beef roast to the skillet and sear it on all sides until browned, about 2-3 minutes per side.
5. Transfer the skillet or roasting pan to the preheated oven.
6. Roast the beef for 20-25 minutes for medium-rare, or until a meat thermometer inserted into the center of the roast reads 130-135°F (54-57°C).
7. Remove the roast from the oven and let it rest for 5-10 minutes before slicing and serving.

You can serve the roast beef with your favorite sides such as roasted vegetables, mashed potatoes, or a side salad. Enjoy!