Cut the potatoes into 1 1/2 inch pieces (do not peel). Steam for 25 minutes or until potatoes are tender.
Heat 1 tablespoon walnut oil in a medium skillet.
Add ham, walnuts, and garlic. Sauté 10 minutes.
Add sherry vinegar, stir well. In a large bowl, toss ham mixture with potatoes, additional 2 tablespoons walnut oil, red pepper, green onions, salt and pepper.
Serve warm or cold with grilled steak, burgers, chicken or fish.