Take 2 tablespoons of butter in a pan and melt it on the stove. Right after that, add flour and give it a good stir to mix it properly.
Cook it for 4 minutes and wait for it to turn brown; you can achieve your choice colour but don; burn it a little light to medium brown is good enough to go with. Right after that, take the pan off the stove and let it sit to cool a bit.
Now take a big saucepan, and melt the remaining butter in it, or you can use the same after emptying it because we will not mix both. Shallots should be transparent when cooking garlic, rosemary, and other ingredients.
When it starts to boil, add the cream. Add the butter-flour mixture, turn the heat down, and let it boil for ten to fifteen minutes. At the same time, you can also add salt and pepper as per your liking.
Last but not least, since we are all ready to serve, heat 1 serving of sauce, add 2 ounces of beef, and let it boil. Now, place a couple of slices of sourdough toast on top of the mixture and top with herbs and paprika, and you are done!!