A recipe for blueberry jam I have stars to run the berries through a food mill. Problem: I don't have a food mill. Can I just whiz them in my food processor instead?
Are you channeling your best self with this comment? (If you're not sure, check out our Code of Conduct.)
You can but you will end up with a more textured jam than if you used a food mill.
If you do want the same silky smooth (and seedless!) texture you would get from a food mill, you can pass the blueberries through a fine mesh sieve after having puréed them in the food processor.
A food mill will remove the seeds and skin for you, basically straining the jam as you "process" the berries. If you have a China cap or mesh strainer, I would push the berries through it using a laddle after the food processor to remove the skin and seeds.
Food mills are inexpensive and an amazing addition to a kitchen. The food processor will not take the 'skins' away.