Cha manao is the Thai name for lemon tea, except that most lemon tea is not made with lemons but actually made with limes as they are home grown, cheaper and more readily available.Although you can buy packet mixes, making it at home is much nicer and you know is free from preservatives. You are also in control of sugar which is a big plus.
Measure out 2 teaspoons of tea leaves and add 1 cup of boiling water. You can either use a Thai style brewing filter bag which is left in the cup and lifted out after brewing. Or use a regular tea pot (with cosy) to brew and use a strainer to filter off the leaves as you pour out the tea. Allow to brew for 4 minutes or so.
Dissolve the sugar in a few tablespoons of hot water
Add plenty of ice to almost fill a large beaker and pour in the hot brewed tea.
Add the lime juice or lemon juice.
Add the dissolved sugar mixture to sweeten to taste.
Video
Thai Iced Lemon Tea - Iced Lime Tea - Cha Manao Yen
Notes
Note 1 - You can use Oolong tea which has a very nice taste or substitute for black tea or green tea if you prefer. Black tea typically has a stronger taste and so you will probably want to reduce the quantity to two teaspoons. Green tea is a little milder.The tea should be fairly strong as it will be diluted when the ice melts on adding the hot tea.Note 2 - The amount of sugar to add is a matter of personal taste. Thai drinks are usually made quite sweet but your preference may differ. Adjust for your preference.Note 3 - Lime juice is used in Thailand but you can also use lemon juice. The taste is not identical but the drink works equally well with either lemon or lime.Note 4 - You need to use an oversized cup because you need enough ice to cool the hot tea down to very cold. Much will melt to dilute the stronger tea you added and the remaining ice will keep your drink refreshingly cold.