There are a few recipe notes before you begin
– For best results, use a salty homemade vegetable broth. Salt is integral to the flavour of the seitan, so if your broth isn’t seasoned then add a teaspoon or so of salt to it.
– You’ll also want to spoon broth over the roast before serving, to keep it from being dry. Of course you’re going to be coating it in gravy, too. But the broth is a nice touch. If you’re slicing and serving, ladle on spoonfuls of broth on each individual slice, too. You can’t have too much juice, here!
– This roast reheats perfectly. Refrigerate in its wrapper for up to 3 days before hand. When ready to serve, preheat an oven to 180°C/350°F/gas mark 4 and cook for 20 minutes. This will dry it out a bit, so use the broth hints above for sure!
– Use a steak knife for the easiest slicing.
– I used storebought breadcrumbs but if you use homemade, use ¾ cup (45 g).
– This makes enough for 6 hungry people. If it’s not Thanksgiving or another holiday, and people are not totally stuffing their faces, it serves at least 8.
First prepare the filling
Preheat a large pan, preferably cast iron, over medium heat. Sauté the mushrooms and leeks in oil until soft, about 10 minutes. Add salt, pepper, garlic and thyme. Cook for about 2 more minutes, stirring often.
Sprinkle in the breadcrumbs and toss to coat. Cook the mixture, stirring very often, until the breadcrumbs are toasty and the mixture is relatively dry. This should take about 5 minutes, and the breadcrumbs should turn a few shades darker.
Drizzle in the broth and lemon juice and toss to coat until moist. If it still seems dry drizzle in a little extra olive oil. Set aside until ready to use.
Prepare the roast
Preheat oven to 180°C/350°F/gas mark 4. In a food processor, pulse the garlic until well chopped. Add the beans, broth, olive oil and soy sauce and puree until mostly smooth (a few pieces of bean are okay, but they should be no bigger than a pea).
In a large mixing bowl, mix together the wheat gluten, nutritional yeast, herbs and spices. Make a well in the centre and add the bean mixture. Stir with a wooden spoon until the mixture starts coming together to form a ball of dough. Knead until everything is well incorporated.
Now we’re going to roll out the seitan and form the roast. Place two pieces of tin foil (about 18 inches long) horizontally in front of you. The sheet further from you should overlap the closer sheet by about 6 inches. This way you have enough foil to wrap around the whole roast.
On a separate surface, use your hands or a rolling pin to flatten the seitan into a roughly 12 x 10 rectangle. If any pieces rip, don’t worry about it, just use a pinch of dough from the ends to repair any holes.
Place the filling in the lower ⅓ of the seitan rectangle, leaving about 2 inches of space at both ends. Make sure the filling is compact, use your hands to form it into a nice, tight bundle.
Now roll! Roll the bottom part of the seitan up and over the filling. Keep rolling until in it’s in a log shape. Now pinch together the seam and pinch together the sides to seal. It doesn’t have to be perfect, it will snap into shape when baking.
Place the roll in the center of the tinfoil and roll up like a tootsie roll, making sure the ends are tightly wrapped. Transfer to a baking sheet and bake for an hour*. Rotate the roll every 20 minutes for even cooking.
* I may update the time in this recipe because I’ve gotten a few comments that said it took up to 90 minutes to cook completely! So for now I would say just do a test my poking the roll with tongs. It should feel very very firm. If it doesn’t, then bake further.
Remove from oven and let cool. Unwrap, slice and serve! (See intro notes for keeping moist and reheating.)