Step 1

Rinse the roast and pat it dry. The roast is triangular in shape. Double-butterfly it in one thin piece.

Step 2

Put the whole piece of meat in a resealable gallon-size plastic bag with the fajita marinade and gently remove the air. Place the bag in a bowl to catch any leakage and place it in the refrigerator for a couple of hours.

Step 3

Light the grill (preferably with mesquite). Put the meat on the hot part of the grill and cook, turning once or twice, until it reaches an internal temperature of 145°F for medium. Remove from the grill and salt and pepper to taste.

Step 4

Cut a test slice to find the direction of the grain, then cut into this strips against the grain. Squeeze lime over the meat and serve immediately with warm flour tortillas and other fajita fixin's.

Step 5

Make Marinade:

Step 6

Combine the pineapple juice and soy sauce in a large mixing bowl. Wash the limes and zest them, adding the lime zest to the juice and soy sauce mixture. Cut the limes in half after zesting and squeeze the juice into the bowl. Throw the lime halves in the bowl, too. Add the garlic. Use as a marinade.