Wife1 taught me about sticking it in the µwave for about a minute per slice, covered with a paper plate to prevent splatter from gooing up the µwave walls.
Works with hard salami, too, if you want something crispy and flavorful for a Dagwood Sandwich addition and don't have any bacon around.
Hint: don't lay the bacon or salami on paper towels to absorb the grease. The slices stick to it and you can't remove the paper. I sometimes use two µwave-proof containers nested together with holes in the top one to allow grease to drip off into the bottom one, but they're a pain in the tush to clean.
Terry, 230RN