Unclued lights (one of three words) are of a kind, as suggested by the title.
 

Across

 
7    Mostly stern examination (3)
11    African’s body to rest briefly (6)
13    One fitted into more extensive counter (7)
15    Entice to enter round dance (5)
16    Having only a small Kazakh coin, couldn’t visit restaurant? (5, two words)
20    Succeeded breaking lyre’s third string, once dismal (6)
21    Place of exile’s back in the black (5)
22    A pound short, issue pork pies in boxes (7)
27    Goes wandering through the Spanish city (7)
29    Less fattening lines include wood sorrel (5, hyphened)
30    With protein, a gram is effective (6)
32    Constant delay, reversing...