In a medium sauce pan, heat the butter until just melted. Add the shallot and cook for 3 minutes. Add the oats and stir occasionally over low heat for 3-4 minutes, until oats and shallots are slightly golden, toasted and fragrant. Add the peas and chicken stock. Stir to combine and cook for 3-5 minutes or until thickened. Stir in 1⁄4 cup Parmesan, lemon zest and mint. Season with salt and pepper to taste and serve with extra Parmesan on top.