Here's a new one for you. But I have to be honest, when I make soup, I don't measure very carefully. I'll try to remember more or less how I made it before I forget.
2 large leeks (or 4 smaller ones)
1 to 1 1/2 lbs of potatoes
6-8 oz mushrooms
1 to 1 1/2 litres (4-6 cups) of chicken stock
Creamo if desired
Salt and pepper
Any other dried or fresh herbs that you like
Trim leeks, use mostly the white and a bit of the light green part. Slice in half length-wise and wash under running water, fanning out the leaves to get the dirt out. Shake dry and slice in 1/4 in half circles.
Peel and cube potatoes, about 1/2 inch chunks.
Heat a little butter and oil in a pot. Saute leeks in the butter for a few minutes. Add mushrooms after a few minutes, and then potatoes a few minutes later. Leeks and mushrooms should be soft, potatoes should be coated and just starting to cook.
Add thyme and any other herbs you'd like. I have fresh thyme, rosemary, basil, and oregano in my garden so I tend to add whatever's handy. Add salt and pepper to taste. I like lots of freshly ground pepper to make the soup 'warm'.
Add about 4-6 cups of chicken broth and simmer until potatoes are cooked. Adjust seasoning.
Add some milk (I just poured some in - maybe a cup or two? - and then I added about 1/2 cup creamo which is higher fat - you can decide)
I'm not sure if this would freeze very well - potatoes get weird when frozen, but you could try it if you want. I just put mine in a container and ate it at work every day for the week.