1. Wander the stalls of a farmers market.
From my experience, the four best markets in Toulouse are (in no particular order) those in Arnaud Bernard, St Aubin, St Cyprien, and Les Carmes. Many of Toulouse’s markets take place every day, but you might want to check the schedule. If you’re looking for free or cheap vegetables, go to the market down Boulevard de Strasbourg. The merchants often leave their unsold veggies / fruits behind when they pack up, and some are pretty much as good as new.