This Trophy is missable
Following along with the main story, Naniko will fill the fridge at your house 1-2 times a month with ingredients for you to spend the evening making boxed lunches.
I got this Trophy on 7/7, and i know i missed at least 1 lunch and stuffed up making another one.
Here is a list of all the different boxed lunches you can make, and the answers so they come out perfectly! The bolded ones are the ones i personally did, any 5 will do though. Try to always make a perfect boxed lunch as it greatly helps towards getting social links up during lunch time for free!
Broiled Fish - Wrap it tightly
California Rolls - Mix and cool simultaneously
Carrot & Burdock Root Kinpira - Add soy sauce and mirin
Chakin Sushi - Thinned eggs
Cream Stew - Dump in all the cold milk
Croquettes - High
Daigaku-Imo - Deep Fry Them
Fried Chicken - Potato starch
Ginger Pork - Score it with a knife
Grilled Fish - Strong heat but from far away
Gyoza - Olive oil
Hamburgers - Cut a hole and look for juice
Kakuni - Mirin, sugar & sake
Marinated Spinach - Strain it
Meat Stew - Simmer with a dropped lid
Mentaiko Pasta - Mayonnaise
Oden - Keep on a low flame and don't boil
Potato Salad - Smash while still hot
Pudding - Vanilla extract
Sweet & Sour Pork - Potato starch
Tonkatsu - Flour, egg, then panko
Vichyssoise - Add lots of milk
Yakiniku Bento - Use soy sauce
Once you finish making the 5th one, the Trophy will pop!