Combine the cashews, honey, oil and some salt in the bowl of a food processor and pulse until a thick paste forms.
For the sandwich:
Slice the bun open and place in a small frying pan with the butter over low heat until toasted and golden brown. Set aside.
With a paring knife, score the foie gras in a diamond pattern and sprinkle with salt and pepper. Heat the frying pan on medium-high heat. Add the foie gras and sear until golden brown on both sides, about 20 minutes.
Spread 1 teaspoon of the honey-cashew butter on the bottom bun and pepper jelly on the top bun. (Reserve the remaining honey-cashew butter for another use.) Place the foie gras on top of the honey-cashew butter and garnish with the strawberry slices, crushed cashews and chopped chives. Top with the jelly bun.