The cat heads straight for the kitchen when it gets a scent of the pizza in the oven. It scrutinises the floor for any ingrediants that fell off when the pizza was going into the oven. She hangs around until your done eating it also. She also seems to like the anise oil I used in the Spritz cookies.
Are you sure you haven’t accidentally confused your jars of orgeno and catnip?
Are you certain he hasn’t confused his cat with a small child of Italian extraction? 
The cat is odd in many ways, and I just thought today “I must share this mundane pointless observation.”
My sister had a cat that loved olives and onion dip.
The cat just finished off some pizza, and has gone back to the living room to lie in the sun.
This is interesting.
Whenever my family would get pizza, one of our cats–the now departed WT–would always hop up and start sniffing and rubbing her face against the box and doing all the general “I love this” cat moves. I can’t remember if she ever indulged in eating any of it, but she sure did love the smell. But neither of our other cats seem to be so inclined. I guess there is a minority of cats who really dig pizza, strange as it may seem.
And no, we never got anchovies, so it wasn’t a fish thing.
When I was a kid we had a Siamese cat who looooved pizza. She would dam near climb your leg to get at it.
My cat Lucy loves pizza. Every time the doorbell rings, she runs to it. She thinks it’s pizza delivery. We brought home pizza this week and she wouldn’t leave the box alone. Rubbing and purring. Finally she just sat on the closed box, stared at me with wide black eyes, and growled. “Give up the pepperoni, you big monkey, and nobody gets hurt.”
Aren’t catnip and oregano part of the Mint family? Or is my cat just nuts?
To my amusement, I’ve discovered that my relatively new kitty Miss Fritters also likes pizza. All she ever gets is my favorite: Pizza Hut plain cheese thin crust, but she likes it. I try not to give her more than a couple of nibbles, though, because she’ll also eat just about anything else you give her, including chicken salad and whipped cream; and I really don’t want her to get sick or fat.
Might I just add… Awwwwww! 
(I was in the pet store yesterday with a friend. There was a little grey kitten that had been MARKED DOWN! And it was meowing at me and rolling around when I petted it! Why must my appartment not allow pets?! 
)
I know catnip is, not sure about oregano. I had a cat that adored mint-flavored Tums. If he found a roll he’d eat the whole thing. He also loved olives and would come running every time I got the jar out of the refrigerator. Just the olive jar mind, not the mayo or mustard or whatever. He always knew.
Oh, a pedantic public service announcement-onions can be bad for cats in sufficient quantity. They can cause red blood cell destruction.
Like two other posters in the thread, I had a cat who loved olives, specifically green olives stuffed with pimiento. Canned black olives didn’t seem to do much, but those green ones - if you weren’t careful, she’d nip your fingers after you were done handling the olives, going after the residual smell and taste.
My cat luuuuurves Pizza too.
She knows now that when I have a certain friend over we’ll pretty much always be ordering a pizza. Once he gets to my house, she takes up position by the door, watching us peruse brochures making dificult cheese-related decisions, ready to mob the pizza boy when he arrives.
When he gets there - She’s up! Up his legs! Trying to climb on the box! One guy has been to my house so many times he asked if we minded him holding the boxes vertically when he got to our door. We let him. She mauls!
She doesn’t let up while we’re eating. It’s the only time she ever bothers me about food - the rest of the time food is considered good but not an urgent requirement. Pizza, however, is a life force that must be consumed at all costs.
We usually just give her some bits we don’t think will harm her and then lock ourselves in the room. With her outside.