Heat 1 tablespoon oil and 15g butter in a medium saucepan over medium heat. Add carrots and mix well with a wooden spoon until the carrots are evenly coated with oil.
Add 1/2 cup water, salt and sugar then cover and cook for about 5 minutes until the carrots are tender.
Uncover and continue cooking for a few minutes while stirring constantly until all the liquid has evaporated and the carrots just start to brown. Take out carrots and set half of them aside then puree the other half with 150ml hot water in the food processor. Leave saucepan as is.
Pour chicken stock in a separate saucepan then cover and simmer over low heat.
Add the remaining oil and remaining butter into the saucepan where the carrots were cooked and heat.
Add onions and saute for 3 minutes until soft and translucent. Add rice and stir for 1 minute with a wooden spoon so rice is well coated with oil.
Add wine and cook while stirring constantly until all the wine has been absorbed.
Stir in carrot puree and cook until it thickens and no longer looks like soup.
Add 1/2 cup chicken stock and stir until almost all liquid has been absorbed. Add the next 1/2 cup of chicken stock and stir. Continue until all most of the stock is used up and the rice is cooked al dente; about 20 minutes. You should have at least 250ml chicken stock left.
Add the remaining carrots (keep a few for garnish).
Stir in mascarpone, Parmesan, 1 tablespoon parsley and thyme. Add the rest of the chicken stock (up to 250ml) in small amounts in order to make the risotto more liquid. Season with salt and white pepper.
Plate risotto and sprinkle with Parmesan, 1 tablespoon of parsley and carrot pieces. Serve immediately.