1. Heat a medium nonstick skillet over medium heat. Add bacon to pan; cook until crisp. Remove bacon, reserving 1 1/2 tablespoons drippings in pan. Crumble bacon. Add crumbled bacon and shallots to pan; cook for 1 minute, stirring frequently. Remove from heat, and stir in vinegar and next 3 ingredients (through sugar). Gradually add olive oil to the vinegar mixture, stirring constantly with a whisk.
Tips: Add the oil slowly, drop by drop at first, stirring constantly with a whisk to get an emulsion. Mustard is an emulsifier and helps stabilize the blend.