Complex sentence: After that, Carell performed with Chicago troupe The Second City where Stephen Colbert was his understudy for a time in 1991, the same year he made his film debut in a minor role as Tesio in "Curly Sue".
Split into simpler sentences: After that, Carell performed with Chicago troupe The Second City in 1991, where Stephen Colbert was his understudy for a time. That same year, he made his film debut in a minor role as Tesio in "Curly Sue".