I mostly eyeball it, but I can share the rough outline of how I put it together, because people have asked, and I don't really mind sharing. Some of the amounts are approximated, but there you are.
1 lb pasta (I like the large, fat, ziti noodles, but elbow macaroni works too; FOR GF: Quinoa pasta tends to be the best pasta substitute)
1/4 cup flour
3 TB oil (TO MAKE GLUTEN FREE: Replace 3 TB of oil with water, and replace flour with potato, tapioca, or corn starch. Best is tapioca. Add AFTER all other ingredients come to a boil, and whisk constantly until thickened.)
2 cups coconut milk thinned with 2 cups water
1/2 cup water, reserved
1 TB miso paste (sweet white miso)
1 TB dijon mustard
1 TB nutritional yeast
2 tsp tahini
1 tsp garlic powder
1 tsp onion powder
3/4 tsp turmeric
1 tsp paprika
salt, to taste
pepper, to taste
Breadcrumbs, tossed in oil (FOR GLUTEN FREE: Substitute crushed almonds or walnuts.)
Set a pot of water on the boil, and cover the lid. It'll boil faster this way. You'll want about 1/2 gallon of water per pound of pasta, so that the noodles don't stick together. While the water comes to a boil, we'll make the sauce.
Start off with a roux (fat + flour, over heat). Over medium high heat, set down a large skillet (larger than you think you’ll need). Add the 3 TB of oil, and ¼ cup of flour. Whisk the two over heat, until the flour smells slightly nutty, and the oil and flour are bubbling slightly. When you’ve reached this light light blond stage (called a blond roux), pour in your room temperature water and coconut milk. Many recipes say to have your liquid hot, but I don’t care to mess up another pan. So nuts to them.
When the sauce (now a béchamel) comes up to a boil, drop down the heat to low (as low as it’ll go), before adding the next set of ingredients. Add the miso, mustard, nutritional yeast, tahini, garlic powder, onion powder, turmeric, paprika, salt, and pepper, and whisk vigorously, until all the ingredients are in a smooth creamy sauce. If it’s thickening up too much, add a few tablespoons of water from the reserved water. I often find that I do need to add water, but your mileage may vary.
Once the water has come up to a full rushing boil, dump in your pasta, and generously salt the water. I’ve been told that it should be salty, like the sea. I grew up in Florida, near the sea, and I know what that means. For those of us who have never been in the ocean, think of it to be as salty as your tears of disappointment at never having been to the sea. This is so that the pasta gets good and salty early on.
Once you have the pasta in the pot, slam on the pot’s lid, so that the water comes up to the boil faster. The sooner your water comes to the boil, the easier it is to prevent it from sticking to itself. As soon as you hear the water in the pasta put bubbling away, and making a boiling noise (it sounds like when you blow bubbles in your juice in the morning to annoy your sister), remove the lid to prevent the pasta from overboiling and making a mess on your stove. Set the timer for 7 minutes. Yes, this means that the pasta will be under-done, but that’s the point. Stick with me.
Now that your pasta is merrily bubbling away in its hot bath, the sauce has had a chance to simmer over low heat for a few minutes. See what we did there? Rather than fussing at the sauce, we let it just relax, and the flavours combine properly. This is important. At this point, you may taste the sauce (but just a little—you want to save some for your pasta, right?) for seasoning. If you feel like it could use a bit more salt, go ahead and add it. If you feel like it has too much salt, panic. No, don’t panic. Just add a bit of sugar until the salt seems to be neutralised. Whisk, whisk, whisk. Right then. Once it’s seasoned to your liking, turn off the heat under the sauce, put on the lid, and let it chill out while your pasta finishes cooking.
Generally, by the time I’ve finished fiddling around with the sauce’s flavours, the pasta would have finished cooking. Drain the pasta once the timer beeps, and put it into casserole dishes. Why? Because this way, the pasta pot is only dirty with water, which is easily cleaned, versus being dirty with sauce too. This way, you can also gauge how many casserole dishes you need without making a big huge mess. My pasta pot’s opening is much narrower than the top of the casserole dish. I make less of a mess when I transfer from colander to casserole dish.
Make sure that the casserole dish is only filled up ¾ of the way. Now pour the sauce over the pasta in the pot. If you do end up having to split the pasta up into two or three dishes, it will have been fairly easy to do if you did it when the pasta is unsauced. Now, toss the pasta in the casserole dish until it’s combined with the sauce. If you have extra sauce, this is very good. Dump that over the pasta in the dish too. It won’t hurt anything.
Finally, sprinkle the tops liberally with breadcrumbs that you have tossed with oil. This is not an optional step. The crispy breadcrumb crust makes it all the more worthwhile. If you don’t have breadcrumbs, run down to the bodega and grab a few packets of soda crackers, and crush them with a rolling pin (while they’re still in the package). That’ll do the same thing.
Bake the casserole dishes (covered for the 1st 15 minutes, then uncovered) at 350°F (180°C) for 20 minutes. If the breadcrumbs on top aren’t browned to your liking, slide the casserole under the broiler for 30 or so seconds. Serve in generous slices, with a side salad of something healthy, so that everyone can pretend that they’re not eating pure indulgence on a plate. Enjoy!