1 ½ kg lamb leg with bone
3 tbsp unsalted butter at room temperature
2 tbsp mild mustard
¼ cup olive oil
3 tbsp fresh thyme leaves
1 tsp onion powder
1 tsp garlic powder
1 tsp salt
½ tsp black pepper
1 whole head of garlic
For the potatoes
1 kg small potatoes, peeled
3 tbsp olive oil
1 tsp salt
½ tsp black pepper
3 sprigs of thyme
3 sprigs of rosemary