Here is the full list of all 21 Delicious - there are Emily's Christmas Carol achievements.
Use every product in every restaurant at least once
Collect all other achievements
Unlock all product upgrades
Walk 1000 miles
Buy all the secret gifts and use them
Buy all shop items
Finish all events and challenges
Finish every level with 3 stars
Find all mice
Finish Santa’s Home
Serve 500 chocolate related products
Find the two turtle doves in the game and reunite them
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
Serve 400 customers quickly