Prepare the pickled red onions, cool and drain. (These can be made in advance.)

In a large sauce pan, place the peas, mint and water. Cover and bring to a boil, then simmer four minutes covered.

While the peas cook, heat the cream and butter to melt the butter either in the microwave or a small sauce pan.

Drain the peas, but retain the water you drained in a measuring cup or bowl.

Pour the drained peas and mint back into the dry pan and add the cream and butter and using an immersion blender, puree. We liked the texture to still be a tiny bit lumpy and not completely pureed but your choice. If you want it smoother, add a small amount of the reserved pea water to thin it down a little and puree further. This puree process can also be done in a blender, but the mixture is very thick. With an emersion blender, you can move the blades around to reach all of the mixture.

Brush a little butter or oil on one side of each pumpernickel square and grill on a ribbed grill pan for a few minutes to brown. Remove and spread the pea puree on the untoasted side and top with a few pieces of the pickled red onion and serve.

You could also toast the bread or serve it un-toasted.