Here I read it should be possible using the NamedEntityGraph, but when the graph gets passed as param to say panache list(queryString, params) with the key being jakarta.persistence.fetchgraph it throws with unexpected param error.

open val entityGraphName: String? = null
protected abstract val klass: Class<EntityType>
suspend fun list(): List<EntityType> {
    return list("entityTenantId = :tenantId", getQueryParams().and("tenantId", tenantId.id)).awaitSuspending()
}

private suspend fun getGraph(): EntityGraph<EntityType>? {
    return if (entityGraphName == null) {
        null
    } else {
        session.map { s ->
            s.getEntityGraph(klass, entityGraphName)
        }.awaitSuspending()
    }
}

protected suspend fun getQueryParams(): Parameters {
    val graph = getGraph()
    return if (graph == null) {
        Parameters()
    } else {
        // https://www.baeldung.com/jpa-entity-graph
        Parameters.with("jakarta.persistence.fetchgraph", graph)
    }
}

I want to avoid writing the queries myself, as the repository inherits from a base class which methods would need to be then overridden.