Add the ham bone and the water to a large stockpot. Bring to a boil over high heat, then reduce heat to low and simmer, covered, for one hour.

Discard the ham bone and strain the broth. Set broth aside.

Increase heat to medium low. Add bacon to pot. Stir occasionally while bacon renders and cooks. When bacon pieces are brown and crispy, remove with a slotted spoon and set aside.

Increase heat to medium. Add the onion, celery and parsnip to the pot. Cook for about 5 minutes, stirring occasionally, until onions turn translucent.

Add potato and corn and stir.

Add ham bone broth (or chicken broth) and thyme.

Add milk.

In a small saucepan, melt butter over medium low heat.

Whisk flour into butter and then add this mixture to the stockpot.

Stir well to incorporate flour mixture.

Simmer the chowder, covered, for one hour over low heat.

If you used chicken broth, taste and season with salt. If you used ham bone broth, between the salt in the ham and the bacon, you shouldn't need to add any additional.

Add black pepper to taste.

Serve with bacon crumbles sprinkled on top.