I freeze peeled cut up parsnips and celeriac (not blanched) into one bag. Then pop them in cold water and bring to boil while peeling some potatoes for a quick roast veg meal.
I also chop onions and freeze in bags so I don’t have prep time of them in mon-fri recipes.
i always cook double of mince recipes, lasagne, cottage pie, spaghetti Bol, potatoes dauphinois and gratins.
I make a lot of recipes from Lucy’s Food (Lucy Cufflin) - minimum effort, maximum impact which she wrote after being inspired by cooking for ski chalet hosted holidays. It brought batch cooking to another level at a time when I needed to be very on the ball regarding cooking time management
I have a large clear tub which I put frozen fruit (mango, peach, raspberries etc) into and keep in the fridge for the base of a quick fruit salad which we have every night. I vary it by adding fresh grapes, kiwi, banana, strawberries etc.
whenever my mum makes quiche she makes me one, I cut it and freeze it, on WFH days I heat it up and have with baked beans for my lunch. (One day I should learn how to make her wonderful pastry bases).