Here is the full list of all 21 Delicious - there are Emily's Christmas Carol achievements.
Walk 1000 miles
Collect all other achievements
Use every product in every restaurant at least once
Unlock all product upgrades
Buy all the secret gifts and use them
Find the two turtle doves in the game and reunite them
Finish all events and challenges
Buy all shop items
Find all mice
Finish every level with 3 stars
Serve 400 customers quickly
Serve 500 chocolate related products
Finish Santa’s Home
Finish Mary's Toy Shop
Finish The Reindeer Farm
Pick up all the nuts the squirrel leaves behind
Finish the Miracle Express
Make 250 combos
Finish George's Train Station
Restock items 350 times
Finish Emily's Snow Garden