Measure the oil into a 10-quart soup pot. Heat over medium flame for a minute or so; add crushed red pepper and garlic, cooking for 30 seconds. Tip in the onions and celery. Season with two teaspoons kosher salt, one teaspoon fresh ground pepper, the thyme, oregano, and bay leaves. Let cook, stirring, for 5 minutes or until softening.
Stir in the carrots, parsnips, potatoes, all of the peas except ½ cup, ham hock, water, and chicken broth. Cover, raise heat to high, and bring to a boil. Uncover, reduce to simmer, and cook 30 minutes. Add the reserved peas. Cook until vegetables are tender (a few peas should have a little bite) and soup is thickened—another 30-40 minutes. Stir regularly throughout cooking time and add a little more water or broth if the soup becomes too thick before it is done.
Taste and adjust seasonings, adding a shake or two of hot sauce to taste. Remove ham hock or shank and let cool briefly. Chop the meat and return it to the pot; discard the hock. Serve hot garnished with a squeeze of fresh lemon or homemade croutons if you like. Serve the seeded tortilla chips on the side.