Pour stock into a saucepan and bring to a simmer. Heat the oil and butter in a separate large pot over medium heat, then add the sliced leek. Cook until softened and sweet, but not coloured, then add the garlic and spice and cook for another minute.
Add rice to pot and cook, stirring until the grains of rice are slightly toasted and each grain is glossy with oil/butter – about 2 minutes. Pour in wine and cook, stirring, until it has been absorbed.
Now start adding a ladleful of hot stock and cook, stirring, until the stock has been absorbed. Continue this process until the rice is al dente and just slightly undercooked, keeping one ladle of stock in reserve.
Remove the risotto from the heat, stir through the last ladle of stock as well as the peas, butter, parmesan and lemon. Allow the risotto to rest for 5-10 minutes.
