Prep the veg - Slice the onion and chop across the slices so that you have little arcs. I like them to be uniform in shape and size, but it's not a big deal. Slice the tomatoes in half and then in half again.
Saute the onion and braise the beans - Saute the onions in a small amount of oil until they have softened. Then add the beans, the broth, the tomatoes, and the herbs. Cover and cook util the beans are very soft and no longer bright green. The tomatoes will break down and infuse the broth.
Crumble the feta and serve - Take the pan off the heat, crumble the feta, and scatter it across the top of the beans. Cover to let the feta melt and get creamy. Serve.