Where I come from, green beans (or just about any kind of beans, for that matter) are cooked low and slow for hours. They need time to absorb all that good flavor of the country ham, onions and other seasoning. You can use any variety of green beans with this recipe (the beans in the photo are Romano) and you can use frozen or drained, and rinsed, canned beans. In my opinion, fresh or frozen taste the best.
In a 4 quart (or larger) dutch oven or stock pot, over medium-high heat, add oil or grease and and ham. (If using ham hock, see step 4.)
Saute for 1 minute, add onion and continue to saute until ham and onions just begin to brown.
Reduce heat to low, add minced garlic and saute for 30 seconds.
Quickly add about 2 cups of water to the pot and increase heat to high. (If using ham hock, add now.)
Add green beans and enough water to cover by at least 1/12 to 2 inches.
Bring to a boil, reduce heat to low/medium-low, cover and let simmer for 2 hours, checking every 1/2 hour to see if additional water is needed.
Add 2 teaspoons ham soup base, cover loosely (to allow some evaporation) and simmer 1 to 3 additional hours, occasionally checking liquid level in pot. (Allow liquid level to reduce to just barely covering the beans.)
Taste beans and add salt and pepper to taste.
NOTE: Small red potatoes may be added during last 1/2 hour of cooking if desired.