For the risotto balls, in a medium saucepan, melt the butter and gently fry the shallot and garlic for 5 minutes, or until softened. Add the thyme and mushrooms and gently fry for 2 minutes. Stir in the rice until coated in the butter. Pour in the wine and allow to bubble for a minute or so.
Add a ladleful of the stock, bring to the boil, and then reduce to a simmer, stirring constantly. Add another ladleful of stock and stir again until absorbed. Continue adding more stock in this way until the grains of rice are plump and creamy. It should take about 15-18 minutes. Fold in the mascarpone and Parmesan. Season to taste with salt and pepper and stir through the parsley. Leave to cool.
For the beef carpaccio, season the beef fillet with salt and pepper. Heat a frying pan until smoking, add the olive oil and sear the beef for 2-3 minutes on all sides, until golden-brown. Remove the beef from the pan and cover in cling film and roll into a barrel shape, twisting tightly at both ends to seal. Refrigerate for 1 hour, or until firm.
When the risotto is cool, use your hands to cover each mozzarella ball with the risotto. Shape into balls.
Heat a deep-fat fryer to 180C. Alternatively, heat the oil in a deep heavy-based frying pan until a breadcrumb sizzles and turns brown when dropped into it (CAUTION: hot oil can be dangerous. Do not leave unattended.). Fry the risotto balls in the hot oil for 4-5 minutes or until golden-brown. Drain on kitchen paper.
For the green sauce, put all the ingredients in a pestle and mortar and pound until you have a thick paste.
Thinly slice the beef and fan it out on a large serving plate. Dot the green sauce around the plate and add the risotto balls. Drizzle with the extra virgin olive oil and top with bull's blood leaves and Parmesan shavings.