Swedish Roast Lamb with Anchovy and Potato Gratin
A Scandinavian showstopper combining salt marsh lamb studded with anchovy and garlic for deep umami notes with creamy potato gratin layered with Jarlsberg cheese. The lamb roasts high then low, developing a golden crust while staying tender inside, while the gratin cooks alongside with whipping cream and milk enriched with crushed garlic and nutmeg. Special because the anchovy paste dissolves into the meat during cooking, adding savory complexity rather than fishiness. Best for dinner parties or celebrations when you want impressive results. Creamy potatoes balance the rich, assertive flavors of the lamb. This version brings together two traditionally separate courses into one harmonious meal, with the potato dish absorbing rendered lamb fat flavors from the oven.
Ingredients
- 4 ½ lb leg of salt marsh lambregular lamb1:1protein
less mineral complexity but still delicious
- 4 anchovy fillets in olive oil, drained, with oil reserved
- 3 fat garlic cloves, peeled
- 1 ¾ tbsp butter, softened
- 3 fresh rosemary sprigs, large
- 2 ¾ tbsp butter, softened
- 1 large onion, halved and thinly sliced
- 10 cups floury potatoes, such as king edward
- 1 ¾ cups whipping cream
- 1 ¾ cups milk
- 1 large garlic clove, crushed
- 1 tsp salt
- ½ nutmeg, freshly grated
- 1 cups jarlsberg cheese, coarsely gratedgruyere1:1dairydairy-free
similar nutty flavor and melt
Instructions
- 1
Heat oven to 450°F/fan 400°F/gas 8. Weigh lamb and calculate cooking time at 16 minutes per 450g.
- 2
Using a small sharp knife, make deep narrow slits all over the leg.
- 3
Cut anchovy fillets in half lengthways, then across into three pieces. Thickly slice garlic cloves and cut into matchsticks.
- 4
Push one piece of anchovy and one to two matchsticks of garlic into each slit.
- 5
Spread softened butter all over the lamb outside and season well.
- 6
Lightly oil a roasting tin with reserved anchovy oil, place rosemary sprigs and leftover garlic in centre.
- 7
Put lamb on top and roast for 15 minutes, then lower temperature to 400°F/fan 350°F/gas 6 and continue roasting for calculated remaining time.
- 8
Melt butter in a pan, add onion and fry gently, stirring, until soft and lightly golden. Set aside.
- 9
Cut potatoes into ¼" thick slices, then across into short matchstick shapes.
- 10
Put cream, milk, crushed garlic, salt and pepper into a large non-stick saucepan and bring almost to the boil.
- 11
Add potatoes, bring back to a simmer and cook for about 10 minutes, stirring gently, until just tender when pierced.
- 12
Stir in onion, nutmeg and more seasoning to taste.
- 13
Grease a 2 litre shallow ovenproof dish with remaining butter.
- 14
Spoon potato mixture into dish and sprinkle with grated cheese.
- 15
Twenty minutes before lamb is ready, put gratin in oven and bake for 30-35 minutes until golden and bubbling.
- 16
Remove lamb from oven, cover with foil and rest for 15 minutes.
- 17
Carve and serve with gratin and vegetables.
Tips
Make slits slightly angled downward and pierce deep into the meat so anchovy and garlic reach the interior where heat can meld them into the lamb rather than sitting on the surface.
Cut potatoes into matchsticks rather than thin slices so they absorb cream while holding their shape through gentle stirring, creating a chunky gratin rather than a puree.
Rest the lamb fully under foil after roasting; carryover cooking continues inside while juices redistribute, ensuring even doneness and easier, more tender carving.
Good to Know
Leftover lamb keeps refrigerated up to 3 days. Potato gratin keeps refrigerated up to 2 days. Reheat lamb gently covered at 160°C. Reheat gratin covered at 180°C until warmed through.
Prepare anchovy-garlic slits and butter lamb up to 4 hours ahead, refrigerated. Prepare potato gratin mixture up to 2 hours ahead, refrigerated. Assemble gratin in baking dish up to 1 hour before baking. Do not fully cook potatoes ahead.
Carve lamb at the table for presentation. Serve with the potato gratin as the primary side, plus steamed or roasted seasonal vegetables like green beans, carrots, or broccoli. A sharp Scandinavian beer or light red wine complements the umami and cream.
Common Mistakes
Use a very sharp knife for slits to avoid crushing the meat; blunt knives tear fibers and allow anchovy to fall out during roasting.
Do not skip the lamb rest under foil; cutting immediately releases juices and dries out the meat significantly.
Stir potatoes only very gently in the cream mixture to prevent breaking them into small pieces, which turns the gratin mushy.
Do not add gratin to oven more than 20 minutes before lamb finishes; potatoes continue cooking and may overcook or dry out.
Substitutions
Dairy-Free Swaps
milder, slightly sweet alternative
General Alternatives
floury substitute with similar texture
less mineral complexity but still delicious
FAQ
Can I prepare the lamb anchovy-studding ahead of time?
Yes, insert all anchovy and garlic slits up to 4 hours before roasting and refrigerate the prepared lamb. Let it sit at room temperature for 30 minutes before roasting so the interior cooks evenly and the crust develops properly.
What if I don't have salt marsh lamb?
Regular lamb leg works fine; salt marsh lamb has a distinctive mineral sweetness, but standard lamb will still taste delicious with the anchovy and garlic flavoring. Cooking time and temperature remain the same. Taste may be slightly less complex.
Can I freeze the potato gratin after baking?
Yes, cool completely, wrap tightly and freeze up to 3 months. Thaw overnight in the refrigerator and reheat covered at 180°C for 25-30 minutes until warmed through. Top may lose some crispness but texture remains acceptable.
How long does the rested lamb stay warm before serving?
Under foil, the lamb stays hot for up to 20 minutes. If carving is delayed beyond this, tent loosely with foil and rest in a warm place rather than a hot oven, which continues cooking the interior and dries it out.