This sentence is from a book of “注文の多い料理店” isn’t it? “とうけん＝当軒” It means this restaurant. We usually use “とうてん＝当店” they’re same meaning. 軒(けん) could use count buildings and houses. For example… 一軒(いっけん)、二軒(にけん)、三軒(さんけん)…etc.. 店(てん) could use count shops For example 一店(いってん)、二店(にてん)、三店(さんてん)…etc…

たぶん　それは「当店（とうてん）」ですね。「この店（みせ）」や「わたしの店」の意味（いみ）ですね。

Hello again. Touken=当軒 The meaning here is “this restaurant”, same as 当店. It’s not used commonly. 当is used for focusing me or us, for example 当方 means we or I. 軒is used when you count houses, for example 家が5軒ならんでいる. Or it is used for meaning a self-employment and you can see, for example, some restaurants name—軒.

it`s a【とうてん】. The kanji is 【当店】. Meaning, it's our store.