Draw the lambda blazon
Charcoal,  17  13 bytes

Thanks to @Neil for saving 4 bytes!

(↙↓⊖θＭ↑(→↗Ｎ‖Ｍ


Try it online!

Explanation:

(↙                // Print '(' and move one step down and to the left.
  ↓⊖θ             // Print n-1 '|'s downwards.
     Ｍ↑          // Move one step up.
        (→        // Print '(' and move one step to the right.
          ↗Ｎ      // Print n '/'s towards the upper right corner.
            ‖Ｍ    // Mirror the left half to produce the right half.