Dan Doherty's Jerusalem artichoke gratin with sweet onion and hazelnut crumble

Name: Dan Doherty's Jerusalem artichoke gratin with sweet onion and hazelnut crumble
Prep time: 40 min
Cook time: 1 h 25 min
Total time: 2 h 5 min
Yield: 8
Ingredients: 600 ml double cream; 1 sprig rosemary; 3 garlic cloves; 400 g maris piper potatoes, peeled and sliced 0.25cm thick (using a mandoline); 800 g Jerusalem artichokes (or celeriac), peeled and sliced 0.25cm thick (using a mandoline); 80 g parmigiano reggiano, finely grated

5 out of 5 stars(1) Rate this recipe

Serves8
CourseMain meal
Prepare40 mins
Cook1 hr 25 mins
Total time2 hrs 5 mins
Plusinfusing

Please note that while we take every care to ensure the product and recipe information displayed on our website is correct, in the event that a product is unavailable, alternatives may be displayed and/or a substitution may be given. This may affect the nutrition and allergen information, therefore if you have any allergy or intolerance, please ensure you have reviewed the product label to ensure it is suitable for you to consume.

Ingredients

600ml double cream
1 sprig rosemary
3 garlic cloves
400g maris piper potatoes, peeled and sliced 0.25cm thick (using a mandoline)
800g Jerusalem artichokes (or celeriac), peeled and sliced 0.25cm thick (using a mandoline)
80g parmigiano reggiano, finely grated

CRUMBLE

40g hazelnuts
50g oats
30g salted butter
2 medium onions, diced
2 garlic cloves, finely chopped
1 sprig thyme
25g flat leaf parsley, finely chopped

Method

Preheat the oven to 180˚C, gas mark 4. Put the cream, rosemary and garlic in a saucepan; season and set over a low heat. Bring to a simmer then take off the heat and set aside to infuse for 20 minutes; strain and discard the aromatics.
Cover the base of a 1.8-litre ovenproof dish with a layer of the infused cream. Add a layer of potato then a layer of Jerusalem artichokes (or celeriac). Season then add another layer of cream, spreading it out to just cover the surface. Repeat all the way up until the dish is full. Cover with foil then bake for 1 hour. Remove the foil, sprinkle the cheese evenly over the top then return to the oven for 20 minutes, or until the Jerusalem artichokes are tender and a butter knife cuts through them easily.
Meanwhile, make the crumble. Spread the hazelnuts out on a baking tray and roast for 8 minutes. Add the oats to one side of the tray and cook for another 5 minutes. Chop the roasted hazelnuts and set aside. Melt the butter in a pan over a medium heat. Add the onions, garlic and thyme; season. Cook slowly for 10-12 minutes, until the onions are soft. Remove and discard the thyme sprig, then stir in the oats, chopped hazelnuts and the parsley. Serve the gratin with the crumble scattered over the top and dive straight in.