In a small dish, whisk together the marinade ingredients then set aside.

Clean and trim the portobello mushrooms. Remove any dirt with a soft towel. Trim the stem if desired.

In a shallow dish, saturate the mushrooms with the marinade and toss a few times to coat. Let them sit for at least five minutes, turning occasionally to absorb the sauce.

Combine the diced avocado, tomato, and finely minced parsley in a small bowl. Sprinkle with salt and half of the hemp seeds. Toss to coat.

Preheat a dark-coated or cast-iron skillet over medium-high heat. Pan sear the seasoned mushrooms until each side browns and the mushrooms begin to soften.

Top each mushroom with avocado salsa and remaining hemp seeds. Serve hot.