Roast Lamb With a Mint Jelly Sauce

Method

1. Take the leg out of the fridge an hour before it goes in. Fridge-cold meat cooks unevenly and you overshoot the outside chasing the middle. Heat the oven to 220°C (200°C fan).
2. Pat the lamb dry all over with paper towel. Wet meat steams before it browns.
3. Make about 12 small incisions across the top with the point of a knife and push a sliver of garlic and a few rosemary needles into each.
4. Rub the olive oil over the whole leg, then the rosemary garlic salt flakes and a good grind of pepper, working it into the cuts.
5. Sit the leg on a rack in a roasting tin with the remaining rosemary and the lemon halves underneath, and roast at 220°C for 20 minutes to colour it.
6. Drop the oven to 180°C (160°C fan) and roast for a further 50 minutes for medium rare, or 65 for medium. The times are a guide; the thermometer is the answer.
7. Check the thickest part, away from the bone: 55°C for medium rare, 63°C for medium. Pull it early, because it gains another 4 to 5°C as it rests.
8. Lift the lamb onto a warm board, cover it loosely with foil and a tea towel, and leave it for 25 minutes.
9. Tip everything from the tin into a jug and let it settle for two minutes. Spoon the fat off and keep 3 tablespoons of the dark juice underneath, plus whatever collects under the resting lamb.
10. Put the mint jelly in a small saucepan over low heat and stir for about a minute until it melts. Keep it below a simmer, then take the pan off the heat.
11. Whisk in the resting juices, then the vinegar and the Dijon if you are using it. Taste, and add vinegar half a teaspoon at a time until it stands up to the fat. Sweetness is the failure mode, not sourness.
12. Stir the chopped mint through off the heat so it keeps its colour, season, and pour into a warmed jug. Carve across the grain and serve.

Leftovers, and the rest of the jar

The sauce keeps three days covered in the fridge. It thickens as it cools but never re-sets, so a splash of hot water brings it back to pouring. Cold lamb, a spoon of it and a piece of bread is the argument for a leg over a rack.

The jar earns its shelf space beyond the roast. Whisk a teaspoon into oil and vinegar for a dressing on tomatoes. Brush it onto cutlets in the last minute on the barbecue, where the sugar catches. And it belongs beside a sharp cheddar, which is why mint jelly is filed under jams and spreads rather than with the savoury jars in gourmet condiments.

Questions we get asked

What is the difference between mint jelly and mint sauce?

Texture, and where each lands. Mint jelly is set with sugar and apple pectin into a firm preserve that holds its shape, so it sits beside the meat in its own dish. Mint sauce is loose and pourable, traditionally chopped mint steeped in vinegar, and it goes over the meat. Same herb, two jobs.

How do you make mint jelly into a sauce?

Melt 4 tablespoons of jelly in a small pan over low heat, below a simmer. Off the heat, whisk in 3 tablespoons of strained resting juices with the fat spooned off, then 2 teaspoons of vinegar, then chopped mint at the last moment. With no roast to draw juices from, use hot chicken stock and an extra teaspoon of vinegar.

What cut of lamb is best for a Sunday roast?

A bone-in leg of about 2kg for six. The bone moderates the heat reaching the centre, so the margin between medium rare and overdone is wider, and the slices hold together on the board. Shoulder is the cut for slow cooking and pulling apart, four hours at 160°C covered.

Can you use mint jelly on anything other than lamb?

Yes, and the acid in it is what makes that work. It goes on a cheese board with cheddar or goat's cheese, melts into the pan juices after roast chicken, glazes carrots or cutlets in the last minute, and whisks into a vinaigrette. Treat it as a sweet-sharp preserve rather than a lamb-only condiment and the jar empties faster than you expect.

If the roast is part of a bigger table, mustards, relishes and sides for ham covers the cold end of the same meal, and four mustards and what they are for sorts out which jar does what. The jelly sits in The Regimental Condiment Company range, $6.95 for the 110g mini and $12.95 for the 310g jar. Orders placed before 12pm on a weekday are dispatched the same day from our Corio, VIC warehouse.