1 cooked pork tenderloin
2 onions, finely chopped
1 tablespoon butter
Couple of teaspoonfuls balsamic vinegar
salt and pepper
For the spread.
2 tablespoons mayo
1 tablespoon Dijon mustard
Zest of a lime
Juice of a lime
To cook a tenderloin visit http://insideabritishmumskitchen.blogspot.com/2011/07/spiced-grilled-pork-tenderloin-with.html
Chop the onions, heat the olive oil and butter and slowly saute the onions until golden brown.
Mix all the ingredients of the spread together and set aside.
When the onions are browning nicely, pour the balsamic vinegar into the pan. Let it bubble and reduce.
When the tenderloin is ready, let it rest for 10 minutes or so.
Slice on the diagonal into thick slices. Squeeze lime juice over the slices.
To assemble the sandwiches, layer with the onions, the baby spinach, the pork and the spread.