Add bacon to a large, deep skillet over medium heat. When the fat begins to render out, add shallots and garlic cloves then saute until bacon is browned but not too crispy, stirring occasionally. Scoop bacon and shallot mixture to a bowl then remove garlic cloves and set aside. Remove all but 1 Tablespoon bacon grease from the skillet then add green beans and turn heat up slightly. Season with salt and pepper then saute until tender, 5-7 minutes, stirring occasionally. Stir bacon and shallot mixture back in then serve.