The prize(s) in question are Zoning Permits and Bonus Crew, and you'll have four opportunities to receive some, as seen below.
Reach Level 3 in ChefVille ---> Receive 1 Zoning Permit and 3 Bonus Crew in CityVille
Reach Level 7 ---> 3 Zoning Permits and 5 Bonus Crew
Reach Level 10 ---> 5 Zoning Permits and 10 Bonus Crew
Reach Level 12 ---> 10 Zoning Permits and 15 Bonus Crew
To be especially clear, you can win a total of 19 Zoning Permits and 33 Bonus Crew, as each prize listed above is a new prize, and not a cumulative total. While 19 Zoning Permits may not be enough to grant you a land expansion, the Bonus Crew should be more than enough to complete at least one or two Community Buildings that require them, so this is definitely an opportunity to take advantage of. Remember, once you reach Level 12 in ChefVille, you'll receive plenty of rewards across Zynga's other games as well, so check each one to see if you're eligible for any other free prizes! Good luck reaching Level 12 and earning these free rewards!
What do you think of ChefVille on Facebook thus far? Have you already reached Level 12, or are you just now starting the game from scratch? Sound off in the comments.