Peel and coarsely chop parsnips. Place in a saucepan and cover with cold water. Bring to boil over medium-high heat. Simmer for 5 minutes until just tender. Drain.
Return saucepan to the heat and add butter, sage and half the oil. Cook for 2 minutes or until leaves are crisp. Remove and reserve a few leaves.
Add apple to pan and cook, stirring frequently until golden. Return parsnip to pan, add milk, reduce heat to low, cover and simmer for 5 minutes until tender.
Purée apples and parsnips in a food processor or with a stick blender until smooth and creamy. Season and keep warm.
Meanwhile, heat a frying pan over medium-high heat. Brush cutlets with remaining oil and season. Cook for 4-5 minutes each side or until just cooked through. Serve with parsnip apple mash and garnish with crisp sage.