We have a granny flat attached to our house (totally separate apart from it shares our front door, the entrance to it is off our hall.) Our lodger is lovely, if a little eccentric, and we've never bothered with a long tenancy agreement because she was a friend of a friend, and on the whole it has worked well. The only thing is, she is obviously not a great cook, and last night she was cooking something that smelt so vile it stunk the whole house out, at 11.30pm! It smelt so horrible I thought there was something wrong with the drains. On reflection, I think it may have been some overcooked, burnt cabbage and lentil dish as she is always on a diet, and is also veggie. I want to say something as 11.30pm is really far too late to be cooking stinky food - and it happens quite often, I sometimes wonder if she is a secret stoner or something - but how do I phrase it tactfully? Just 'XXXX, please could you not cook smelly food late at night?' That's fair enough, right?Although I wouldn't mind it smelling if it actually smelt nice, it's the fact it smells like she's boiling rotting body parts that's the problem.