Preheat oven to 375°.
In a large stainless steel pan, cook the chopped bacon over medium high heat until it just starts crisping. Remove the bacon and set aside, leaving the fat in the pan.
Turn the heat under the pan off, and carefully add the halved brussel sprouts to the pan. Residual water from the rinsing may cause the bacon grease to jump out of the pan at you!
Add the salt and pepper to the pan, and toss the brussel sprouts several times to make sure they are thoroughly coated in bacon grease, salt, and pepper.
Place in the oven, and roast for 30 minutes. After the 30 minutes, add the bacon and pecans, and toss to combine. Return the pan to the oven, and roast for another 15 minutes.