In a bowl, mix quinoa, carrots, vinegar, and salt. Set aside.

In a small bowl, gently toss hearts of palm with mayonnaise and Old Bay. Set aside.

Place a sheet of nori on a bamboo sushi rolling mat. Spread 1/2 cup of the quinoa mixture onto 2/3 of the nori sheet.

Arrange about 2-3 spoonfuls of the hearts of palm mixture across the top of the nori sheet. Add a few slices of avocado, cucumber, and green onion.

Dab some water across the bottom of the nori sheet to help seal the filling. Roll the nori tightly but gently pulling the mat out of the way with each turn.

Let the sushi roll rest on its seam for a few minutes while you repeat this process to make thew remaining 4 rolls.

Whisk the dipping sauce ingredients together. Slice the rolls into 6-8 pieces.