Remove the beef from the fridge an hour before cooking and let it come to room temperature.
Heat the oven to 220˚C / 200˚C fan / Gas 7.
In a small bowl, mix together the oil, chopped herbs, garlic and seasoning.
Place the onion and carrot in the bottom of a roasting tin to create a tripod. Place the beef on top and spread the herb mixture over the beef. Add the sprig of herbs and the garlic bulb.
Put it all in the oven for 20 minutes.
Reduce the oven temperature to 180˚C / 160˚C fan / Gas 4 and calculate the remaining cooking time (10-15 minutes per 450g for medium-rare, 15-20 minutes per 450g for medium, and 20-25 minutes per 450g for well-done meat).
Make the glaze by putting all the ingredients in a small pan and bringing it to the boil, thickening and simmering until it has a syrupy texture.
When 15 minutes of cooking time are left, pour most of the glaze over the beef and return it to the oven.
Check to see if the beef is cooked to your liking, take out, brush the meat with the remaining glaze and scatter the crispy onion on top. Allow to rest before cutting.
Recipe by Elwen Roberts (Hybu Cig Cymru) - Prynhawn Da.