Prepare rice according to package directions.
Meanwhile, in medium bowl, toss together hearts of palm, cucumber, tomatoes, red onion, lime juice, jalapeño and salt. Fold in avocado. Refrigerate for 10 mins.
Divide rice among 4 serving dishes; top with ceviche. In small bowl, whisk mayonnaise with yuzu juice; drizzle over top.
Garnish with finely chopped fresh cilantro if desired.
For a restaurant-style presentation, just before serving, pile rice and then ceviche in layers using a circular mold to create a ceviche “tower”.