Apart from the restaurants in the Cite Medieval we can recommend the restaurant at Chateau Pennautier. You will pass this on your way to Ventenac, it’s on the left before you cross the river coming into Pennautier. The food is good but don’t ask for a beer or a whisky - they only serve wine and it’s their wine at that. Though it is quite good.
There is an excellent Logis de France restaurant at the village of Aragon a few km north of Ventenac. This is one for special occasions.
Histoire Gourmand in Carcassonne is well worth a visit. It is located at the top of Rue Barbes
Cabardes is a wine appellation and there are many vineyards where you can taste before you buy. Some of them also have restaurants attached, particularly if you travel over to the Minervois area.