I occasionally buy pre grated cheese - I did when my food processor was broken for example, and I but grated mozerella for pizza, and freshed grated/shaved parmesan too
I buy frozen Yorkshire puddings for DD and her friends after school
I sometimes buy pre-prepared salad, leaves and veg - for when I am in a rush after work they can be handy sometimes.
I once needed to make a very quick casserole for DD and her friend - I bought chopped everything, even onion, on my way home, threw it in a pot and into the oven, wennt out to get DD and friend and it was ready by time home almost.
I sometimes by prepared packs of fruit such as for DD's odd picnic lunch or snack. She likes pineapple and melon but we don't often use a whole one quick enough
I always have frozen chips/wedges in the freezer