In a large pot, melt the butter. Stir in the vermicelli and pine nuts and cook over high heat until golden brown, 3 minutes. Stir in the rice. Add the chicken stock, 1 teaspoon of salt and 1 teaspoon of white pepper. Cover and cook over low heat for 25 minutes, until the rice is tender and the stock has been absorbed. Uncover, fluff with a fork and cover again. Let stand for 20 minutes. Stir in half of the mint; season with salt and pepper. Transfer the rice to a bowl. Garnish with the remaining mint and serve right away.