Chop 1 beetroot into 1 cm dice, and set aside for the garnish.
In a food processor or blender, puree the other beetroots. Peel and finely dice the onion.
Peel and crush the garlic cloves. Pick the leaves off the thyme sprigs.
Grate the Parmesan.
Boil a kettle full of water.
In a wide saucepan, heat the olive oil.
Sweat off the onions until they become translucent. Add the garlic and thyme and cook out for about a minute. Add the arborio rice, and stir to coat each grain with oil.
Stir in the white wine, and cook out until the pan is nearly dry.
Add the pureed beetroot, and a ladle full of the boiled water. Before adding the next ladle of water, make sure all liquid has been absorbed by the rice.
Keep adding water until the rice is cooked through yet still firm.
Stir in the grated Parmesan and butter until it is completely absorbed.
Mix together the diced beetroot into the mascarpone, until it takes on a bright pink hue.
Stir into the risotto, but try to leave apparent streaks.
«You can use any root vegetable for this risotto: in fact, roasted swedes would be perfect for Burns night.»