Step 1

Light a grill or heat a grill pan. Set the steak flat on a work surface. Using a sharp knife, carefully cut through the center of the steak (parallel to the work surface), leaving 1/2 inch of the meat attached at the side so it can be opened like a book. Set the butterflied flatiron steak in a medium bowl or baking dish.

Step 2

In a blender, combine the orange juice with the chipotle, adobo, garlic and 1 tablespoon of the olive oil and puree until smooth. Pour the marinade over the steak and let stand for 10 minutes.

Step 3

Meanwhile, in another medium bowl, gently mix the avocados with the corn, red onion, jalapeño, lime juice and the remaining 1 tablespoon of olive oil. Season with salt and pepper.

Step 4

Remove the steak from the marinade, letting the excess drip back into the bowl; do not wipe off the marinade. Season the steak with salt and pepper. Grill the butterflied steak flat over moderately high heat, turning once, until medium, about 6 minutes on each side. Transfer the steak to a cutting board, cover with foil and let rest for 5 minutes. Thinly slice the steak across the grain and serve with the avocado-corn relish.