Heat olive oil in a large saucepan over medium heat.
Add shallot and cook until softened, about 3-4 minutes.
Add garlic and cook until fragrant, about 1 minute.
Add Sungold tomatoes and cook until they burst, about 5-7 minutes.
Add Arborio rice and toast for 1-2 minutes.
Pour in white wine and stir until absorbed.
Add warm stock one ladleful at a time, stirring constantly until absorbed before adding the next.
Continue until rice is creamy and al dente, about 18-20 minutes.
Stir in Parmigiano-Reggiano, mascarpone, and butter.
Season with salt and pepper to taste.
Garnish with fresh basil and extra Parmigiano-Reggiano.
