Fantastic Lebanese veggie / vegan menu at Flandres de Liban (website even has English menu) in Wazemmes.
More centrally, Aux Indes, do a great veggie set lunch and dinner - but you have to ask for it.
And don't miss trying a 'palette' of four (small) different beers at Les Trois Brasseurs close to the old Lille Station (Lille Flandres, rather than the Eurostar station).
www.flandresliban.net/
Aux Indes is at 38, Rue Thiers, Lille