Place the peas in a large pot or bowl, cover with water by 2 inches and soak 8 hours or overnight. Drain the peas and set aside.
In a large pot, melt the butter over medium-high heat. Add the onions and cook, stirring, for 2 minutes. Add the celery and carrots and cook, stirring, until just soft, about 3 minutes. Add the garlic and cook, stirring, for 30 seconds.
Add the ham hock and ham and cook, stirring, until beginning to brown. Add the drained peas, salt, pepper, and pepper flakes, and cook, stirring for 2 minutes. Add 8 cups of water, the bay leaf and thyme, and cook, stirring occasionally, until the peas are tender, about 1 hour. (Add more water as needed, if the soup becomes too thick or dry.)
Remove the bay leaf and discard. Adjust the seasoning, to taste, and serve immediately with Parmesan Truffled Chips on top.