Add the diced onion, minced garlic and a knob of butter to a heavy base large frying pan on medium heat. Sauté until the onions become transparent.
Add the arborio rice followed by the white wine and stir. Allow to simmer for a few minutes before gradually pouring in the stock while continuously stirring. Allow the rice to absorb the liquid before pouring in further stock,then add the thyme.
Once the rice has completely absorbed all of the water then add the pumpkin purée and stir through and allow to absorb for 5 minutes.
Add the grated parmesan cheese and a good pinch of cracked pepper, stir through.
In a smaller frying pan add a knob of butter followed by the sliced mushrooms and the thyme. Sauté until the mushrooms become golden brown. Remove from the heat.
To serve, spoon the pumpkin risotto into bowls, add the sautéed mushrooms over the top and sprinkle with parsley and parmesan cheese.