events-by-tea-flavour.php

<?php
add_action( 'init', 'register_tea_flavours', 100 );
add_action( 'parse_query', 'focus_on_events_for_tea_flavour_queries' );

function register_tea_flavours() {
	register_taxonomy( 'tea_flavours', TribeEvents::POSTTYPE, array(
		'label' => 'Tea Flavours'
	) );
	register_taxonomy_for_object_type( 'tea_flavours', TribeEvents::POSTTYPE );
}


function focus_on_events_for_tea_flavour_queries( WP_Query $query ) {
	if ( ! $query->is_main_query() ) return;
	if ( ! $query->get( 'tea_flavours', false ) ) return;
	$query->set( 'post_type', TribeEvents::POSTTYPE );
}