Place potatoes in a large saucepan and add water to barely cover. Add salt, cover loosely and bring to a boil.
Reduce heat and cook for 12 minutes or until potatoes are almost cooked through. Drain and cool.
Cut potatoes lengthwise into slices.
Slice asparagus spears into thirds.
In a skillet, warm butter and oil over medium heat. Cook potatoes and asparagus for about 10 minutes or until potatoes are golden brown on both sides and asparagus is tender (stir occasionally).
Remove from heat and season with salt and pepper.