The Sauce:

Roughly chop pear, add to a blender or food processor along with the garlic and minced ginger. Pulse several times, then with the blender or food processor running, slowly add the 1/4 cup water. Once the mixture is broken down, add the brown sugar and pulse until a smooth puree is formed. (Stop to scrape down as necessary throughout the above steps.)

Scrape the puree into a small saucepan. Stir in the remaining ingredients (soy sauce, Mirin, rice vinegar, toasted sesame oil, and gochujang or Sriracha).

Bring to a low simmer over medium heat and cook until thickened, stirring now and then, about 10 minutes. (Sauce will thicken a little more once cooled.) Remove from heat and cool before placing in a clean (preferably glass) container. Makes about 2 cups. Reserve about a third of a cup to brush over the tenderloin while cooking, pass the remainder at the table.

Note: It is very likely the recipe will make more sauce than necessary. This will keep in the fridge, tightly covered for two to three weeks. May be frozen.

The Tenderloin:

Prepare tenderloin, removing any silverskin. If large, turn over to the rough side and make several shallow cuts the length of the tenderloin to help it lie flat. If small, consider tying.

In a plastic bag large enough to hold the tenderloin, add the marinade ingredients: soy sauce, mirin or sherry, rice wine vinegar, grated ginger, garlic, sesame oil, cooking oil. Marinate for at least 1/2 hour and up to overnight.

Grill:

30 minutes before grilling, remove tenderloins to room temperature and pat dry. Prepare grill for 2 zones, both direct and indirect heat. If using gas, heat one side to medium-high and leave the other side unlit. For a charcoal, light coals, on one side of the grill, leaving the other empty.

Place the tenderloin over the hot side of the grill. Cover and cook, turning once, until the internal temperature reaches 140°F to 145°F, 5 to 7 minutes per side. (Temperature chart in above text.) Move to indirect side once charring is to your liking, and continue to cook until desired temperature is reached, another few minutes. Remove and rest the tenderloin, lightly covered for about 10 minutes before slicing.

Oven:

Preheat oven to 425 degrees F. with a cast iron skillet (to ensure a good sear, later) inside. When hot, remove skillet, add a tablelspoon or two of oil and sear tenderloin on all sides. Place skillet back in oven and roast for about 15 to 20 minutes, turning once, until desired temperature is reached. Again, refer to the chart in the body of the text. Remove and rest the tenderloin, lightly covered for about 10 minutes before slicing.

Nutritional Information based on 6 servings and half the sauce: