1

To make the sauce: In a medium bowl, whisk the sauce ingredients. Cover and refrigerate until about 20 minutes before serving.

2

In a large skillet, cook the bacon over medium heat until crispy, about 10 minutes, turning occasionally. Drain the bacon on paper towels. Pour off [and reserve] all but 2 tablespoons of the bacon fat in the skillet. Add the garlic to the pan; cook for about go seconds, stirring occasionally. Add the spinach; cook until the spinach is wilted, 1 to 2 minutes, stirring constantly. Place the spinach mixture in a medium bowl. Add the raisins and 1/8 teaspoon of pepper. Finely chop the bacon and add it to the bowl. Stir the mixture and allow it to cool to room temperature.

3

Trim the tenderloin of any excess fat and silver skin and allow to stand at room temperature for 20 to 30 minutes before grilling. Using a long, narrow knife, make a hole in the center than runs the full length of the tenderloin. Turn the knife over and cut to expand the opening. Stuff the spinach mixture into the hole from both ends using the handle of a spatula or wooden spoon. Using kitchen string, tie the beef into a compact, even cylinder. Lightly brush the beef all over with some of the reserved bacon fat [or olive oil]. Season with the dill and salt and pepper to taste.

4

Sear over Direct Medium heat for 15 minutes, turning a quarter turn once every 3 to 4 minutes. Continue to grill over Indirect Medium heat until cooked to desired doneness, 20 to 30 minutes longer for medium-rare, turning once. Remove from the grill and let rest for 5 to 10 minutes. Carefully cut into 1-inch slices. Serve warm with the sauce.