In a large pot over medium heat, warm the oil. Add the onion and ½ teaspoon salt. Cook until softened, about 3-5 minutes, stirring occasionally. Stir in the greens, broccoli, herbs, garlic, fennel, red pepper flakes, and ½ teaspoon salt. Cook for 1-2 minutes, stirring occasionally.
Pour in 4 cups water, bring it to a boil, then reduce the heat to a simmer for about 3-5 minutes or until the broccoli is fork tender. Transfer everything from the pot into a (large) high-speed blender and blend on high until smooth, allowing steam to escape (if you have a smaller blender, do it in two batches or try with an immersion blender). Pour back into the pot.
Stir in the remaining 4 cups water, pasta, chicken, beans, soy sauce, and remaining ½ teaspoon salt. Bring the liquid to a boil over high heat, give it a stir, then reduce the heat to medium to maintain a rapid simmer for 10-15 minutes (check the chicken after 8 minutes) or until the chicken and pasta are cooked through, stirring often to prevent the pasta from sticking to the bottom of the pot.
When the chicken is done (155-160F), transfer it to a cutting board. If the pasta is not cooked and the water level is too low or too thick, add in some more water and keep cooking (pasta cook times vary a lot).
Shred up the chicken and stir it back into the pot along with the lemon juice. Taste and add more salt or lemon, if you think it needs something.
In a small bowl, mix together the feta, parsley, lemon zest and black pepper.
Serve topped with the feta topping or cheese of choice and a generous drizzle of good olive oil.