The mildly nutty flavor of a fresh fava bean pairs perfectly with the creamy mascarpone and basil oil in this delicious soup. Go for the fresh beans when you see them in the Spring.
Heat the olive oil in a large pot over medium heat, add the shallots and cook until soft, about 5 minutes. Add the potatoes and stock and bring to a boil then reduce to a simmer. Cook, uncovered for about 8 minutes, then add the fava beans and peas and cook for another 8-10 minutes and the potatoes are tender. Turn off the heat, and toss in the basil leaves to wilt them.
While the soup is simmering in a large mixing bowl, make an ice bath with ice and water. Sit another large bowl in the ice bath (preferably a metal bowl).
Ladle the soup into the bowl over the ice bath to quickly cool down the soup. This will preserve the brightest color from the beans, peas and basil.
Once cooled, carefully add the soup to the carafe of a blender, and, in two batches, purée until smooth. Pour back into the saucepan and stir in the heavy cream until fully incorporated. Season with salt and pepper to taste.
To serve: Delicious at room temperature or chilled.
Divide the soup among the serving bowls. For each soup, add a dollop of the mascarpone, a drizzle of Basilolio, and a sprinkle of white pepper over the top.