Why, search the interwebs, of course.
It's taken a few iterations, but here's what I have settled on as my favorite version:
Close-enough Swedish Meatball Gravy
(cobbled together from various recipes)
NOTE: Technically you're supposed to de-glaze the pan the (from scratch) meatballs were cooked in with the stock but that hasn't happened yet at my house.
1/2 cup dairy*
(*half&half, cream, or most of a 5 oz can of evap. milk <-- what I use)
2 Tblsp flour
1 cup beef stock*
(*I use a cup of water with good-quality beef soup base, aka bouillon)
1 Tblsp soy sauce
Salt & Pepper
(opt. step 0.) De-glaze the meatball pan with the stock. Ha.
Heat the stock to boiling, Add flour to dairy, whisk till blended. Add slurry and and soy sauce to stock, return to boil, and simmer till thickened. Add s&p to taste.
Soy sauce? Yes, soy sauce. Believe it or not, it shows up in multiple "authentic" recipes I found. I have also discovered that I like the evaporated milk version the best. Besides, evaporated milk is the perfect emergency coffee creamer, so go get some right now. Some recipes add a little nutmeg. Seems like a good idea, but I haven't tried it yet.
Make up some boiled or mashed potatoes, crack open the jar of lingonberry jam,and you're good to go. If I'm feeling generous, I'll saute up some cabbage to stand in for a vegetable.