Heat the oil over medium high heat in a Dutch oven or big pot until hot.
Toss in the chopped onion and cook until the onions are transparent (about 5-10 min).
Add the garlic and stir.
After 30 seconds or so, pour in the tomatoes (with juice).
Drain and rinse the beans and add them to the pot.
Add the ham bone, basil, water, and pepper.
Reduce the heat to low, cover the pot, and continue cooking for about 15 minutes until flavors are blended.
If you don't have a ham bone, you can substitute ham bouillon, or simply leave it out. Add salt if you leave out the ham.