Bacon Mushroom Dip

1. Cook bacon in a large skillet over medium heat until crisp, about 5 minutes per side. Drain on paper towels. Pour off rendered bacon fat, reserving 1/4 cup. Wipe skillet clean. Coarsely chop bacon.
2. Return 3 tablespoons bacon fat to the skillet. Add leek and garlic; cook over medium heat, stirring occasionally, until translucent, about 2 minutes. Add fresh mushrooms, then the salt and pepper. Raise heat to high; cook, stirring, until mushrooms are tender, 5 to 8 minutes. Add thyme; cook 2 minutes more. Transfer to a plate; let cool.
3. With an electric mixer, whisk cream cheese in a medium bowl until smooth. Gradually add sour cream and blue cheese crumbles and whisk until fairly smooth. By hand, stir in mushrooms, three-quarters of the bacon, scallions, and 2 tablespoons beef broth at a time until the desired consistency is achieved. .
4. Garnish dip with scallions and remaining bacon.