Vegan Garlic Mashed Potatoes for a Week

I adapted my mashed potatoes recipe to feed something like 30 people. As a result, mashed potatoes are the only Thanksgiving leftover I have not come close to losing to overenthusiastic noshers, and I feel rather smug about that. The pumpkin pie is gone; the gravy is a mere puddle of its former self, and at this point the cranberry sauce functions only in a cosmetic way. But I can continue to reap the benefits of Thursday's feast with my mashed potatoes.

Mashed potatoes can be turned into so many things, like mashed potato cakes…and potato bread rolls…and I don't know, some sort of shepherd's pot pie lid or something. Whatever. I just like these mashed potatoes with everything.  I was thinking of cooking up a big pot of parselyed crowder peas, and they would go quite well with my potatoes.

So for all you future feasters, here is my Vegan Garlic Mashed Potatoes For a Crowd:

Cooking time: about 1 1/2 to 2 hours.

1 entire bag Yukon Gold potatoes, probably 8-11 medium
3 heads garlic plus 1 extra clove garlic
3 full sprigs fresh rosemary
about 1/4 Cup extra virgin olive oil
sea salt and fresh ground black pepper

1.  Cut off the tops of the 3 heads garlic. Peel the garlic until it's only got one layer left. Drizzle the open tops with olive oil. Wrap the 3 heads of garlic in aluminum foil and roast them in the oven at 350ºF for about an hour until oozy and soft. (You can do this step a day or two in advance.)
2. Scrub all the potatoes but don't peel. Plop them in a tall pot. Cover generously with water and bring to a boil. Simmer until a fork can easily pierce the middle of the fattest spud. Drain and return to the hot pot.
3. Meanwhile, wash the rosemary, de-stem it, and chop up the leaves. Add them to the olive oil. Peel and mince a raw clove of garlic. Add that too. Add a generous helping of sea salt and pepper. Let the mix marinate at room temperature for at least a half hour. 
4. With a hand-held potato masher, bluntly smash all the cooked potatoes into bits. Squeeze the tasty innards from the roasted heads of garlic directly into the potatoes. Add the oil-rosemary-garlic mixture. Mix them all up thoroughly.
5. Serve hot to the multitudes.