- STEP 1
Pre heat oven to gas mark 5 ( fan 190c) 357 f.
- STEP 2
Push slice of garlic and rosemary into 24 deep cuts.
- STEP 3
Season meat with salt and pepper as desired.
- STEP 4
Cut onions and place in bottom of roasting tin with a little water, and place lamb on top of the onions. Cover with foil and cook for 1.5 hours. Remove foil and cook for a further 30 mins.
- STEP 5
Remove lamb from the oven, cover with foil and rest for 20 mins.
- STEP 6
Sauce:- cook onions in butter gently for 5 mins - do not let them colour. Bruise rosemary leaves with pestle and mortar to release their oil. Chop finely and add to onions. Cook gently for 15 mins.
- STEP 7
Stir flour into onions and buttery juices til smooth, gradually adding milk and stock bit by bit whilst whisking vigorously. Simmer for 5 mins.
- STEP 8
Remove from heat, liquidise half and return
- STEP 9
to saucepan to other half. Reheat and add creme fraiche and pour into serving jug