Preheat oven to 350 F /177 C. Grease and flour a bread pan. (In my experience, these breads tend to release quicker and easier from glass pans than metal. Metal pans work, but you may have to be more patient with them.)
If you're not using a stand mixer, mash the bananas before mixing them with the butter and sugar. If you are using a stand mixer, cream butter and sugar, then add chunks of bananas. Beat well until bananas are well mashed. Beat in eggs.
Add salt, baking soda and part of the flour. Pour in milk and lemon juice, then add remaining flour. Mix well. Add ground walnuts and flaxmeal. If making the chocolate chip version (try it--it's so good you'll wonder why you haven't been putting chocolate chips in your banana bread until now!), add in chocolate chips and extra flour (unless you already included it--I often make a double batch because I have one kid who prefers it sans chocolate, so I mix it all up, pour one loaf's worth of batter into a pan, then add the chocolate chips and extra flour to the remaining batter. If you're just making the chocolate chip version, simply put in the total 1 3/4 cups of flour when you add your flour in).
Pour batter into prepared pan. Bake at 350 F/ 177 C for 60-65 minutes, until a toothpick inserted in the center comes out clean.
Allow bread to cool in the pan for at least 10 minutes. Then loosen the bread around the edge of the pan with a knife. Give the pan a couple of shakes to loosen the bread completely, then sit it on a cooling rack or cutting board to cool. If your bread does not fully loosen with a couple of good shakes of the pan, put it down and back away from the bread. Give it more time to rest and come back to try again in 10-15 minutes. It will come loose if you've greased and floured your pan, but sometimes it likes to hold on tight to the bottom for a while. If you force it by banging on the sides of the pan to loosen it, you'll likely be tearing it, leaving chunks of the bread bottom stuck to the pan when you tip it out. (I speak from frustrated experience.) Metal and ceramic pans tend to do this more than glass ones, in my experience, but no matter what your pan is made of, have patience, Grasshopper.
Let bread cool completely before slicing or freezing. This bread freezes beautifully sealed in a zip-top bag. When you take it out of the freezer, simply let it thaw before slicing and enjoying.
Notes
Recipe adapted from my friend Anita Anderson Cooper.*Ground walnuts are walnuts chopped up incredibly tiny by running them through a food processor. It's a sneaky/clever way to get these healthy nuts into your baked goods without big chunks of nut meat (which I personally don't appreciate). You'll never even know they're there because they don't change the texture, not even in this soft, buttery quick bread.