Preheat the oven to 425°F.
Rinse and scrub the fingerling potatoes and then blanch in boiling salted water for 5 minutes, Remove with a slotted spoon and let cool down. DO AHEAD...this can be done a day before.
Blanch the bacon in the boiling water from the potatoes for about a minute, remove with a slotted spoon, and transfer to a paper towel. DO AHEAD. This can be done a day ahead too.
If you did the day ahead prep, remove all of the prepared items from the refrigerator and let come to room temperature, for about an hour.
In a heavy oven-proof skillet, cook the bacon on medium high heat to render and cook the bacon to just prior to crispy, about 10 to 12 minutes.
Carefully pour the rendered fat into a bowl.
Transfer the bacon to a piece of paper towel.
Add back 4 to 6 tablespoons of the bacon fat to the pan over a medium high flame.
When the fat is hot, add shallots and sauté for about 3 to 4 minutes.
Add the sprouts to the pan and continue to sauté for another 5 minutes. Adding more fat if needed.
Add the potatoes and toss to coat with bacon fat.
Season with salt and freshly ground pepper, and stir the pan.
Place the pan into the oven and roast for about 30 minutes or until the shallots and sprouts brown.