Make the mash:

1. On medium high heat, in large pot, cover potatoes, garlic and bay leaves with water and bring to a simmering boil. Cook until potatoes are tender and easily split with a fork.
2. Remove from heat, drain all water. Remove bay leaf.
3. Add butter, salt and pepper and mash until smooth.
4. Season to taste with more S & P.
5. Set to chill for a couple hours (the more chilled it is, the easier it is to make).

Assemble the Wellington

1. In hot pan, wilt 3 large handfuls of spinach, strain and squeeze excess water.
2. Preheat oven to 200c/400f.
3. On parchment paper, add thawed puff pastry sheet. Add baby spinach, spread out evenly over pastry.
4. Add potato and shape into a cylinder and roll evenly.
5. Close each end to contain contents, use a small amount of butter or water, to help seal the pastry into form.
6. On baking sheet, bake potato Wellington for 30 minutes until golden brown.
7. Set to chill for a couple hours before slicing.
8. Once chilled, slice into half finger length size pieces.
9. Reheat in oven on parchment lined baking sheet.