Yes, you CAN live without Universal Binding Ingredient!!! Try making the following, instead:
Melt 3 tbs butter in a heavy-bottomed saucepan over medium heat. Add 4 tbs regular flour to it. Cook, stirring constantly, until the flour no longer has a "raw flour" smell to it. If the flour is starting to brown (and if you don't want it to brown - you probably don't, for this recipe), then turn the heat down a bit. Once the roux is cooked (since that's what you've just made - now you can also make various creole recipes, cook a wide variety of sauces, make a base for a souflee, etc.), add milk and/or cream (try about a cup at first, and add more if necessary) and stir, until you have a sauce of the thickness and consistency that you need. It may take about 3 or 4 minutes to thicken up properly, so don't go whole hog with adding more milk or cream until you've seen how thick (or not thick) it's going to get. Add salt and pepper to taste and voila! - you have basic univeral binding ingredient, but made fresh out of wholesome ingredients.
If you like, you can sautee sliced mushrooms and herbs in another pan (first sautee the sliced mushrooms over medium-high heat in butter till they've fully juiced out and the juice has largely evaporated, leaving lovely browned mushrooms, then add the herbs at the end), with or without sauteed onion and/or garlic, and then add the milk or cream sauce.
You could also add shredded cheese to the sauce (cheddar, provolone, parmesan, etc.) along with sauteed onion, to make a cheese sauce.
You could, in fact, add any number of yummy things to it to give it the appropriate taste for the cassarole, souflee, sauce, or whatever it might be to which you're adding it. The world is your oyster.