>>54773
I prioritize high calorie meals as much as possible. Since protein keeps you feeling full, I try to feed her as little protein as possible while maximizing carbs and fats. By doing this, since she's not getting a lot of protein (making her stay full), I'm hoping it'll make her eat more food throughout the day, causing her to gain weight. The less full she feels, the more she eats. The more she eats, the more weight she gains
Foods that are high in both carbs and fats are pasta, dairy, cheese, heavy cream, butter, bread/breading, etc. Then of course there's desserts like pastries, chocolate, ice cream, pie, chips, and so forth. You can buy meals using those ingredients but I recommend learning how to make them yourself so you can adjust the ingredients to your liking
You're already doing what I do with the pasta dish. If the recipe calls for 2 tbsp of butter, I double it. If it calls for 1 cup of heavy cream, I either double it or add a little extra. Since I'm focusing on just carbs and fats, it lets me give her larger portions to compensate for the decrease in protein
Some dishes that I feed her are penne vodka, chicken Alfredo, butter chicken curry, and mac & cheese. If I buy her food, it's any of those or I get her fast food. Some things that I get her are sandwiches, French fries, chicken tenders, burritos, potatoes, and usually a milkshake or sweet drink
My SO also has a pretty big sweet tooth so I make sure to stock the house with her favorites. After a day of eating like this, I'll wake up next morning and usually find some candy bar wrappers or an ice cream pint in the trash. Sometimes I'll find two ice cream pints in the trash which is about 2,000 calories on top of everything else that she ate in the day. You want to keep food highly available for her