Step 1

You will need a pan to roast the meat, either a roasting pan or a 9x13 pan, and a pan to saute the vegetables.

Step 2

Lay the pork tenderloins onto a cutting board, and cut the pieces lengthwise down the middle to butterfly each tenderloin (see photo) by making approximately a 2 inch incision, unfold the tenderloin like a book.

Step 3

Pat the meat dry with paper towels.

Step 4

Drizzle about 1-2 tablespoons of olive oil on the inside surface of the meat, sprinkle generously with salt and pepper. Set aside until ready to stuff tenderloins.

Step 5

In a large frying pan, saute onions in 2 tablespoons butter and 2 tablespoons olive oil until soft over medium heat about 4 minutes.

Step 6

Add 3-4 cups or about half of the sliced mushrooms to the onions in pan. Set rest of mushrooms aside for gravy.

Step 7

Increase heat in pan to medium high, continue stirring and cooking mushrooms until soft, about 4-5 minutes. Salt and pepper to taste.

Step 8

Cook until mushrooms start to turn golden, add chopped garlic cook for one additional minute.

Step 9

Remove mushrooms and onions from heat.

Step 10

Preheat oven to 450 degrees and place rack in middle of oven.

Step 11

Spread the cooked mushroom and onion mixture evenly down the middle of the pork tenderloin. You may either roll and secure the filling inside, or simply place the filling in the middle of the pork and secure with toothpicks. Sprinkle outside of pork with a little salt or garlic salt.

Step 12

Add 1 tablespoon olive oil to pan used to saute onions and mushrooms.

Step 13

Heat the pan to medium high and then sear the meat on all sides, this takes approximately 2-3 minutes if pan is heated properly.

Step 14

The meat should be a rich golden color on all sides.

Step 15

Remove the meat and place seam side up in a roasting pan or 9x13 pan , do not wash pan.

Step 16

Pour 2 tablespoon soy sauce and 2 tablespoons balsamic vinegar down the seam (where toothpicks secure the roast) over each stuffed tenderloin roast so the sauces will soak into the filling and center of the tenderloins.

Step 17

Bake for 15-18 minutes at 450 degrees. Set meat on counter for at least 15 minutes before cutting.

Step 18

Prepare gravy while meat is resting. If preparing gravy in roasting pan, set meat aside onto another plate so the plate will catch the juices.

Step 19

Melt 4 tablespoons butter over medium heat in same pan used to cook onions and mushrooms.

Step 20

Add remaining sliced mushrooms and increase heat to medium high.

Step 21

Add salt and pepper to taste, stir fry mushrooms until golden brown.

Step 22

Sprinkle mushrooms with 1/4 cup flour, stirring while adding flour.

Step 23

Slowly add 2 cups chicken broth to pan, stirring while adding broth.

Step 24

When mushroom gravy is thickened a bit, add the drippings from the roast this will give the gravy a rich, dark color. Stir until all juices are combined.

Step 25

When ready to serve, remove toothpicks gently from meat.

Step 26

Place meat onto cutting board.

Step 27

Slice tenderloins into 3/4 to 1 inch thick pieces.

Step 28

Carefully place meat on platter by sliding a long knife or spatula under cut meat and remove to a platter all at once.

Step 29

Spoon gravy down center of meat just before serving.

Step 30

Serves approx 6-8