It’s not so easy for everyone. There are many different minhagim and Chumros. For example, in Lubavitch, we don’t eat Gebrokts, only use hand made shmurah matza (obviously) don’t use many spices and herbs, only eat peeled fruit and vegetables, anything that can’t be peeled isn’t used, and we don’t buy any processed foods, with the exception of Matzah, Wine, Salt, Sugar (some boil it) and some use out, while others only use Shmaltz.
So anything we eat was 100% prepared by us, all out of raw ingredients. We don’t even buy potato starch.
(Preempting the questions, of course there are some Lubavitchers who aren’t careful with these Minhagim, but that doesn’t change the fact that it is Lubavitch minhag, and kept by the vast majority. Also, any Pesach hotel that advertises “All Chabad Chumros” is an oxymoron.