Real French-Kanadian split pea soup needs to be slow-cooked for at least an hour and a half, preferably two hours. I use a slow-cooker and let it cook all night. The longer you let it simmer, the better it will taste. The problem is, you’re supposed to start with dried peas, so your peas are going to turn to mush before it’s done. I prefer a bit more substance to my peas, personally, but it won’t be inedible.
Don’t worry about preparing the ham first. Just dice it and add it to your peas, then add your spices (thyme, garlic, cracked peppercorns, and BUTTER; make sure you add the butter, since you aren’t using ham hocks to add extra fat – without the butter, it won’t taste like pea soup), any vegetables you’re adding (I recommend celery and carrots) bring it to a boil, and then let it simmer for an hour and a half to two hours.
My mother was French-Kanadian, so I grew up on split pea soup, tourtiere, and nun’s farts.
Edit: As long as it’s been kept below freezing, food will keep forever. It may lose flavour, but it’s still perfectly safe to eat. Scientists have safely consumed frozen mammoth, for example.