Glazed Lamb Loin with Red Onion Jam
This unique lamb loin recipe pairs a quick-to-fix red onion jam with tender, pan-seared lamb and a subtle, Guinness-based glaze.
Boneless lamb loins are a tender, quick-cooking cut with a rich meaty flavor that pairs well with sweet-and-savory condiments like our easy-to-make red onion jam.
For this recipe, we give the lamb loins a nice sear on both sides, brush on a glaze made with Guinness stout, sugar, garlic, and thyme, and finish the cooking in the oven for maximum tenderness.
The red onion jam is easy to make as well. It simply involves caramelizing the onions to a jam-like consistency by adding a bit of sugar and splash of Guinness for extra flavor.
When used in cooking, Guinness stout adds a subtle, bittersweet flavor to food. In this dish it’s used to balance both the richness of the lamb and the sweetness of the onion jam.
Because boneless lamb loins are so easy to prepare, and the jam and glaze can both be made ahead, this dish is a nice choice to serve for a casual company dinner.
Lamb is not only popular in Irish cuisine, it’s a staple in Mediterranean cuisine as well. Browse our full collection of lamb recipes for more inspiration.
Guinness Glazed Lamb with Red Onion Jam
- 1-1/2 lbs boneless lamb loins, see notes
- Olive oil
- Salt and freshly ground black pepper
- 1 clove garlic, minced
- 4 tablespoons Guinness Extra Stout, divided
- 4 teaspoons sugar, divided
- 1 tablespoon fresh thyme leaves
- 1 large red onion, quartered and thinly sliced
- Preheat the oven to 400°F.
- If necessary, trim the lamb of any excess fat. Rub all sides with a bit of olive oil, season with salt and pepper and set aside while you prepare the glaze and onion jam.
- For the glaze, heat 1 tablespoon of olive oil in an oven-proof frying pan over medium heat. Add the garlic and sauté until fragrant, 1 minute.
- Stir in the Guinness and 3 teaspoons of the sugar and continue cooking, stirring constantly, until the mixture reduces to a syrupy consistency, 2 minutes. Add the thyme, transfer the mixture to a small bowl and set aside.
- Return the pan to the stove and add another tablespoon of olive oil along with the onion. Season with salt and pepper and sauté over medium heat until the onion is soft 7 to 8 minutes.
- Sprinkle with the remaining teaspoon of sugar, add 2 tablespoons of water and continue cooking until the liquid has evaporated and the onion is lightly caramelized, 4 to 5 minutes longer.
- Add the remaining tablespoon of Guinness and scrape up any browned bits that may have accumulated on the bottom of the pan with a spatula.
- Continue cooking, stirring often, until the onions reach a jam-like consistency, 3 to 4 minutes more. Taste and adjust the seasoning if needed, then transfer the jam to a small serving bowl and set aside.
Note: The natural flavor of the hops in the Guinness adds a hint of bitterness to both the jam and the glaze in this recipe. We like this flavor to remain subtle, but you can add a little more beer to the jam if it suits your taste. Just adjust the cooking time to accommodate for the extra liquid.
- Wipe the pan out and place it back on the stove over medium-high heat. Coat the bottom with a bit of olive oil and sear the lamb loins on all sides, 2 to 3 minutes total.
- Brush the glaze evenly over the top of the lamb and place the pan in the oven to finish cooking, 5 to 7 minutes for medium-rare (130 to 135°F).
- Allow the lamb to rest for 7 to 10 minutes before slicing. Serve with the onion jam.