Direction :

1. In a large pot, heat the oil over high heat. When it shimmers, add the onions, carrots, celery, and cumin seeds or ground cumin. Season with a pinch of kosher salt. Give it a stir. Turn heat to low. Cover and cook for 15 to 20 minutes or until vegetables have lost their firmness and have softened a bit.
2. If you haven’t rinsed your split peas, do that now. Let drain in a sieve.
3. Uncover the pot, add the garlic, and cook for about a minute. Add the ham bone, bay leaf, and split peas. Add 8 cups of water. Season with a pinch of salt. Bring to a boil; then lower heat so that everything is just simmering. Check the soup at 30 minutes and give it a stir. You likely will need to add more water. I consistently add at least 2 more cups of water. Season generously (if you wish) with pepper.
4. Cook for at least 15 minutes more (roughly 45 minutes total, though depending on your split peas, it may take more or less time). Taste. It’s done when the split peas have totally broken down. Add salt to taste. (Note: Depending on your ham bone, you will need to add more or less salt, so taste the soup, and add salt as needed to ensure it is seasoned to your liking.)
5. Remove the ham bone. Retrieve any large hunks of meat that may have fallen into the soup off the ham bone. Remove any pieces of meat clinging to the ham bone. Dice up the ham and add it back to the soup. If it wasn’t a particularly meaty ham bone, you may want to add more diced ham to the soup — it’s totally up to your tastes and preferences — it’s delicious without ham; it’s delicious with ham.  Once the ham has been added, give it a stir, and one final taste. Season with salt and pepper to taste.
6. To make croutons: Dice up 3/4 pound bread (roughly). Place in a bowl. Toss with about 1/4 cup olive oil and season with salt to taste. Toast in the oven at 425ºF for 10-15 minutes or until golden to your liking. 
7. Serve soup topped with croutons or with bread on the side. See notes above for freezing.