One of the ideas I got from my new ‘modernist’ friends is to prepare vegetable fondant sous-vide. I tried it with parsnips as a side for the lamb with our Easter dinner, and it turned out great. I had never heard of vegetable fondant, but it seems to be very popular in restaurants in the UK. Root vegetables or potatoes are browned in fat and subsequently cooked in stock. It is relatively simple to do, but quite tasty as both the stock and the browning will add some nice flavor to the vegetable. This technique can also be used for potatoes, celeriac, sweet potatoes, carrots, etc.
It can be cooked without sous-vide as well, but the nice thing about the sous-vide preparation that it is easier to cook the vegetables perfectly tender with some bite to them, neither undercooked or overcooked, and that you need less stock to cook them. With conventional cooking on the stove or in the oven, you’d need enough stock to almost cover the vegetables. With sous-vide you only need enough to coat them. If you don’t own a chamber vacuum sealer, you must freeze the stock in cubes or use ziploc pouches to be able to vacuum seal the vegetables with the stock.
I opted to cook the parsnips until they were quite soft, so the browning added some nice flavor but they didn’t get crispy. If you like them crispy, cook them for a shorter time and/or at a slightly lower temperature (83C/180F) and do not pour the sauce over them.
homemade stock (vegetable, chicken, lamb, beef, fish, depending on your preference and what you are serving it with), simmered down to ‘demi glace’ thickness and frozen in cubes, about 1 cube per parsnip
fresh thyme leaves, about 1 tsp for each parsnip
(clarified) butter or olive oil
If needed, you can keep the parsnips warm or reheat them in the water bath while the meat is cooking sous-vide. At such a temperature, in this case 57C/135F for the lamb, the parsnips will stay warm but won’t ‘cook’ any further.