This Thai restaurant in Castle Hills City offers a wide range of options for vegetarians and vegans, including a separate vegan menu with many appetizers and entrees. The atmosphere is trendy, romantic, and cozy, making it a great spot for dates or groups. The service is generally excellent, with friendly and attentive servers who are happy to make recommendations. However, there have been some issues with slow service and one staff member being rude to customers. The food is delicious and flavorful, with many options for both lunch and dinner. One of the standout dishes is the Spicy Mango Delight, which is a must-try for anyone who loves Thai food. The restaurant also offers a variety of vegetarian and vegan options, including a separate menu for vegetarians. The location is convenient, with plenty of parking available. Overall, Thai Topaz is a great option for anyone looking for a delicious and authentic Thai meal in a trendy and cozy atmosphere.