Put the potatoes into a large pot and cover with cold water. Bring to a boil over medium heat and add a generous pinch of salt. Cook for 8 minutes so they are tender but still slightly firm. Strain and let them cool. When they are cool, cut them in half and carefully scoop out the insides using a teaspoon or melon baller to form a cup. (Reserve the scooped out insides for Round 2 Recipe Shrimp and Potato Salad with Sour Cream and Bacon Dressing).
Preheat the oven to 400 degrees F.
Put the potato cups into a large bowl, add the oil, rosemary and season with salt and pepper, to taste. Carefully toss the potato cups to coat them with the oil. Arrange the potatoes, cut side up, on a baking sheet and bake until the cups are browned and crisp, about 15 to 20 minutes.
While the potatoes are baking, put the bacon into a cold skillet and cook over medium heat until crisp. Drain the bacon well on a baking sheet lined with a brown paper bag. (Reserve 2 pieces of bacon for Round 2 Recipe Shrimp and Potato Salad with Sour Cream and Bacon Dressing.) Chop the remaining 6 pieces.
In a bowl stir together the sour cream, mustard, 1 tablespoon chives, the chopped bacon, and salt and pepper, to taste. Arrange the potatoes onto a serving plate and fill each with a spoonful of the sour cream and bacon mixture. Garnish with the remaining chives and serve immediately.