### Clue: Very little in Catholic teaching initially was read during troubles (4,3)
### Answer: RIOT ACT 
 ### Explanation: Definition: was read during troubles
 IOTA(a very small amount of something) **contained in**(in) RC(abbrev. for "Roman Catholic"/Catholic in short) + **1st letter of**(… initially) "teaching".
Answer: Originally, an Act of Parliament in Great Britain introduced during a time of civil disturbance; the phrase "to read the Riot Act", in common usage, is to give a stern warning or telling off to anyone who causes/is going to cause trouble.