I was going to crack a joke about me slippin' her so much meat she wasn't capable of more real meat - but then I realized you were serious.
My wife would probably talk with me first - and explaining why she felt we should et veg.meat, but if I was as stubborn as my brother she would introduced it secretly, and then had a "real" introduction of it. When I (my brother) would say "Get this crap off my table" she would reply with a grin she's been feeding me this for three months
Just to repeat what most others say: Talk to her!
(If she goes "You have NO busines looking in the fridge"-defencive approach...you could be on to something
)