Prep the vegetables:
Cut all vegetables into large chunks. (Shortcut: I love buying pre-cut veggies from Seasons to make this extra easy.)
Sear the flanken:
In a large soup pot, heat a bit of oil over medium-high heat. Add the flanken and sear on both sides until nicely browned. Remove to a plate.
Add the onion to the pot and sauté until browned. Add the remaining vegetables and garlic, and cook for a few minutes to bring out their flavor.
Add your seasonings, return the seared flanken to the pot, and add the herbs (bundle them in a bag or cheesecloth for easy removal). Pour in water until everything is covered.
Bring to a boil, then reduce to a simmer. Cover and cook for 3–4 hours, until the flanken is tender and the broth is rich and golden.
Remove the herb bag before serving. Ladle into bowls and enjoy—this broth is the kind that makes you go back for seconds.