There are a few ways to make gravy. This method is just one, and it works best for Old School pot roast because of the amount of water you have to work with.
Now that the meat and vegetables have cooked for several hours in the liquid, you’ve got a nice beef broth. All you must do now is thicken it. The Damsel has seen normally well-adjusted people run crying, faces in their hands, at the thought of making homemade gravy, because they’ve heard their reputation as a cook rises and falls on the ability to make lumpless gravy. Don’t worry. The Damsel will hold your hand, and your reputation’s safe.
Remove the nice, tender slab-o-beef to a platter. Hopefully it’s so tender you’ll have to be careful, or it will fall apart as you move it. Take out the potatoes and carrots, too, with a slotted spoon. Cover them both with foil to keep them warm while you make the gravy. This only takes a few minutes, so get the kids setting the table.
Turn the heat up on the pan that now contains only the broth. There should be quite a bit…4 to 6 cups, maybe more, maybe less. A smaller remainder, like 2 cups, could be caused by evaporation during the long cooking period, but if you have a tight-fitting lid for your pot, most of the liquid should remain. You can add water if you need to end up with more gravy. Spike it with some beef bouillon if you add more than a cup.
While that comes to a boil, put about a cup of flour in a jar. A canning jar will work if one’s lying around handy, but any jar with a lid is fine. Add COLD water at a ratio of about 1:3, (one cup flour, 3 cups water) but please don’t measure. It ruins the magic.
It needs to be cold water because hot water will sort of cook the flour, and that will make it LUMPY!!!!
Put the lid on the jar and shake it. HARD. Shake it until the flour and water are completely mixed.
Position yourself in front of the stove, armed with the jar in one hand and a whisk in the other. When the broth is boiling, shake the jar one last time, take the lid off, and pour a small stream into the boiling broth, while stirring madly with the whisk. Pour in about half of the flour mixture, and stir for a minute or two. The broth should look somewhat gravy-like now, opaque rather than clear. If you’d like it thicker, add more flour mixture, stirring all the while. Remember that it takes a minute or so after an addition for it to thicken. If you get it too thick, it’s okay. You can add water, a little at a time.
Lumps are usually caused from the flour/water mixture being lumpy, so if you’ve shaken that well, you should be good to go. You can use the blender to make the flour/water mixture if the shaking thing isn’t working for you. And, there’s no shame in putting the gravy in the blender, either, if you still end up lumpy. Or use an immersion (stick) blender if you like.
Onion floaties from the onion soup mix don’t count as lumps and are perfectly fine.
Cook and stir for a minute or two to make sure the flour’s all cooked. Add plenty of salt and pepper and taste. Then taste it again poured all over a plate of roast and veggies.