Chop & prepare all veggies. Dice carrots, peel & chop potatoes (about 1/2 inch cubes), Trim Broccoli heads into smaller pieces, cut zucchini (about 1/2 inch cubes.)
Shred the cheese.
Make a Roux in a Large Pot, using 4 TBSP butter and 4-5 TBSP fresh milled soft white wheat flour. Cook butter & flour until raw flour smell is gone, and it starts to thicken a bit.
Season with salt & pepper
Add diced onion if using, if not skip to step 6.
Add longer cooking veggies to the pot like, potatoes & carrots. Cook for a few minutes on Medium - Medium High. Stirring frequently, so not to burn any ingredients.
Then, add the quicker cooking veggies to the pot, such as, broccoli, zucchini, etc. Cook for a couple minutes while stirring. Season again with a little salt and pepper, and dried minced onion.
Now, add 6 cups of water + 2 TBPS veggie base (or broth,) then turn heat to high, and Stir to make sure nothing is sticking to the bottom of the pot.
Once it comes to a boil, and all the veggies are softened (about 8-12 mins depending on veggies and cut sizes) then, turn down heat, and slowly add in shredded cheese (not all at once.)
Stir until cheese is melted through.
Then, take your 1 cup of milk, and add some of the hot soup to the milk to "temper" it. Now, slowly pour the warmed milk into the soup, and stir.
Once milk is all combined, and the cheese is melted, it is ready to serve.
This can be served in regular bowls and garnished with a bit more cheese & green onion (if desired), but I highly recommend this soup in a bread bowl!
Checkout my site for a great sourdough bread bowl recipe (but, I would recommend making the bread bowls the day before, so they are ready to go!)