Cook the bacon according to the instructions on the package.
Remove from the pan and pour out half of the bacon grease. (You should have about 3 tablespoons of bacon grease in the pan.)
Once the bacon has cooled slightly, cut the slices into small pieces. Set aside
Place the pan back on the stove over medium heat and sprinkle in the flour.
Whisk continuously until the flour starts to bubble and turns a light brown color.
Whisk in the salt and pepper and let the mixture thicken for another 30-45 seconds.
Pour in the milk and whisk the entire time.
Continue whisking and cooking until the gravy starts to simmer.
Reduce the heat to low medium and whisk until the gravy thickens (about 5 minutes).
Mix in the bacon pieces and remove from the heat.
Let it cool for 3-4 minutes to allow it to thicken more before serving over biscuits.
Store leftover gravy in an airtight container in the refrigerator for up to 3 days.