Place the entire mound of risen dough into the pan you'll use to bake the focaccia. (I used a deep, 10" x 16" pan.)
Pour in the bacon grease and knead it into the dough, stretching and folding the dough to work it in. Once most of the grease has been incorporated, add all of the crisp bacon pieces and the rest of the grease. Continue to stretch and fold the dough until every inch if the dough feels like it has bacon pieces in it.