Tofu and vegetables:
1 cake tofu, prefrozen and thawed (more info)
1 large carrot, diced
1/2 large yellow onion, diced
1 medium-large Yukon Gold potato, peeled and diced
2/3 cup frozen peas, thawed
Poultry seasoning
Olive oil
Bechamel sauce:
1.5 tbsp butter (real butter, please!)
1.5 tbsp flour
2.25 c milk, cream, or half-and-half...choose your fat level
1 tbsp worcestershire sauce
2 tsp vegetarian broth powder, preferably "chicken flavor"
Slice the tofu into 1/2" thick slices if you didn't already slice it before freezing. Squeeze out the slices and spread them out on a tray lined with paper towels. Shake poultry seasoning liberally over the slices and press the seasoning in with your fingers. Turn over the slices and repeat seasoning and pressing in on the other side. Leave them to sit for at least an hour; room temperature is OK.
Heat about 1 tbsp olive oil in a medium skillet over medium heat. Add the potatoes. Let them sit still for 7-8 minutes to brown on one side, and then turn them over. Let sit another 3-4 minutes, and then add the carrot and onion. Let cook for about 10-15 minutes, until onion is clear and carrot is firm but cooked and potatoes are done, sauteeing every 3-4 minutes to cook evenly and prevent sticking. Add the peas and remove from heat. Set the vegetables aside.
In a medium-sized heavy saucepan, heat the butter over medium heat until melted. Sprinkle in the flour and use a whisk to scrape the bottom of the pan and mix the fat and flour thoroughly. DO NOT walk away from this. Keep moving the whisk in the mixture as it cooks. It will take on a nutty smell as it cooks. (This mixture is a roux, and this technique is a classic technique for preparing a bechamel or any other white sauce based on a bechamel. You know that canned cream of mushroom soup that your mom used in casseroles? That stuff is for people who don't know how to or can't be bothered to make a bechamel. Once you taste a fresh bechamel, maybe with added mushrooms, you won't go back. I promise you, this is worth the effort. </foodsnob>). When the roux takes on a coppery color, add about a half cup of the milk or cream. It will bubble up angrily and seem scarily on the verge of burning, but don't be intimidated...keep your whisk moving rapidly, and before you know it the roux will be turning into a thick paste. Add the rest of your milk, whisking constantly and scraping the bottom frequently. Cook the bechamel over medium heat, stirring almost constantly and scraping the bottom and sides with the whisk to prevent burning, for about 10 minutes until the sauce has thickened nicely. Remove from the heat and add the worcestershire and the broth powder; stir to incorporate.
Bake the shells according to package directions. Dice the seasoned tofu and toss it with the vegetables. Pour the sauce over the vegetable-tofu mixture. Heat in the microwave if necessary. Spoon the mixture into the empty shells, top with shell lids, and surround the shells on each plate with additional filling. Bask in the compliments and the exclamations that this couldn't possibly be tofu that tastes so good.