Step 1

Preheat oven to 230°C / 450°F (210°C fan).

Step 2

Marinade/rub: Mix the Marinade ingredients in a small bowl. Rub all over the lamb surface, getting it right into all the cracks and crevices!

Step 3

Marinate 2 - 24 hrs: If time permits, marinate for 2 hours on the counter in a roasting pan, or up to 24 hours in the fridge. I skip this step more often than not, however. (Note 4)

Step 4

Prepare roasting pan: Scatter onion in the base of the roasting pan. Place lamb shoulder on top . Pour water into pan.

Step 5

Roast uncovered for 45 minutes.

Step 6

Slow-roast 12 hours: Turn oven down to 100°C/210°F (both fan and standard, Note 5). Cover lamb with baking paper, then a double layer of foil and seal very tightly to avoid moisture evaporation. Roast for 12 hours (I always do overnight!).

Step 7

Check meat – Test side of lamb with two forks. The meat should be fall-apart tender. If not, cover and return to oven.

Step 8

Remove lamb: There will be a lot of liquid pooled under the lamb in the roasting pan! Remove lamb to a large dish. Cover loosely with foil to keep warm. It will stay warm for 2 to 3 hours. See Note for reheating / making ahead.

Step 9

Reduce liquid: Strain all the liquid in the roasting pan into a saucepan. Bring to a boil then simmer rapidly on medium-high until it reduces down to 1 cup (250ml).

Step 10

Thicken: Mix cornflour with water. Pour into jus in a thin stream while stirring continuously. Continue to cook for a minute or two over medium heat, stirring every now and then, until it thickens to a syrup consistency. Add salt and pepper to taste.

Step 11

Serve Slow Roasted Lamb with Jus. Use tongs for tearing meat off - no knife for carving needed! Pictured in post with Greek Lemon Roasted Potatoes, a perfect match for this Greek-ish flavoured lamb. Roasted Vegetables would also be ideal.