Scrub the celeriac well with a brush to get any dirt out of all the nooks and crannies. Line an 8" square pan with two overlapping sheets of aluminum foil and place the celeriac in the middle. Rub it all over with olive oil, salt and pepper. Bash up the garlic, and throw it into the foil packet with the thyme and 4 bay leaves. Top the celeriac with the miso paste and more olive oil, then wrap the entire thing up tight. Bake in a preheated 375 degree oven for two hours. If you like, you can peel back the foil 15 minutes before you take it out of the oven, to get some colour on the top. The sauce/gravy will take about 15 to minutes to make.

Start by chopping the onion and mincing the final two cloves of garlic. Place a large pan over medium heat and heat up a tablespoon or two of olive oil. Add the onion and cook, stirring occasionally, until translucent, about 5 minutes. Add the garlic and stir until fragrant.

Slice the mushrooms and add them to the pan, adding additional olive oil if needed. Let them cook down about 5 minutes, then deglaze the pan with a little white wine. Add 1 cup of stock, the remaining bay leaves, and reduce the heat to a simmer. Allow the whole thing to reduce for about 5-10 minutes, until thickened.

Now add the coconut milk, the mustard and stir it in, as well as the greens. Allow the whole thing to cook down together for another few minutes, adding additional stock if it gets too thick. Taste and adjust seasonings.

Remove the celeriac from the oven and place it on a pretty plate. Pour the gravy over top and around the celeriac. Slice the celeriac at the table and serve with the mushroom gravy.