“Mixed salad” does not mean that the word “salad” is mixed, but there are jokes. This was posted on Sickipedia on July 6, 2017:
     
In the restaurant the special of the day was dalas
I asked the waiter “what’s DALAS ?”
He said. “Mixed salad” 
   
     
Sickipedia
In the restaurant the special of the day was dalas
I asked the waiter “what’s DALAS ?”
He said. “Mixed salad”
Joke by Bigboy in Jokes With No Home - Ironic · July 6, 2017
 
Twitter
Bob Kostic
@causticbob
In the restaurant the special of the day was dalas
I asked the waiter “what’s DALAS ?”
He said. “Mixed salad”
6:28 AM · Jul 6, 2017·Twitter Web Client
 
Twitter
Snooo2 Chelsea Blue
@twosnoot2
In the restaurant the special of the day was dalas I asked the waiter “what’s DALAS ?” He said. “Mixed salad”
2:24 PM · Jul 6, 2017·Twitter for Android
 
Twitter
Spock Thornaby
@Spock_Thornaby
Yesterday in a restaurant the special of the day was dalas I asked the waiter “what’s DALAS ?”  He said. “Mixed salad”
3:13 AM · Aug 27, 2017 from Walthamstow, London·Twitter Web Client
 
Twitter
Bob Kostic
@causticbob
In the restaurant the special of the day was dalas
I asked the waiter “what’s DALAS ?”
He said. “Mixed salad”
8:41 AM · Jul 7, 2019·Twitter Web Client
 
Twitter
Tim O’Neill
@dezignguy
In the restaurant the special of the day was dalas
I asked the waiter “what’s DALAS ?”
He said. “Mixed salad”
7:26 PM · Oct 12, 2019·Twitter for iPad