As someone with no firsthand experience with Lebanese food I can’t offer any opinions about “authenticity”

But the Phaidon cookbooks are beautiful and they have one The Lebanese Cookbook https://www.amazon.com/dp/0714879096/ref=cm_sw_r_cp_api_i_ES80ENKVTD1GQ7ZFN1RY

Also if you want one in the cheap I’d recommend

Limited-time deal: Rose Water and Orange Blossoms: Fresh & Classic Recipes from my Lebanese Kitchen https://www.amazon.com/dp/B00THMCC7G/ref=cm_sw_r_cp_api_dl_6Y8V5JRS1AVFPGFE94PE

It’s $4.99 for the kindle version right now.

Also consider these bargain kindle cookbooks more broadly on “middle eastern cuisine” all around ~$5 or less.

1. Feast https://www.amazon.com/Feast-Islamic-World-Anissa-Helou-ebook/dp/B07257Z6CV/ref=zg_bs_156154011_5/147-6966048-9516535?pd_rd_i=B07257Z6CV&psc=1

2. Sweet

https://www.amazon.com/gp/product/B01NAW3RDM/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i0

1. Flavor

https://www.amazon.com/gp/product/B0841N95PJ/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i1

1. Jerusalem

https://www.amazon.com/gp/product/B007SGM160/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i5

1. Plenty more

https://www.amazon.com/gp/product/B00JTCJEMK/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i3

Also Claudia Roden’s Arabesque which includes Lebanese food is a steal at $7.99 for the kindle version

https://www.amazon.com/gp/product/B001O1O7W6/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i3