Soak the cashews. Place raw cashews in saucepan and cover with water. Bring to a boil. Reduce heat and simmer covered for 10 minutes. *Note: If you do not have a high speed blender you can instead grind your cashews using a coffee grinder. In this case you do not need to soak the cashews before grinding them.
While cashews are simmering, press your tofu. Drain water from the tofu packaging. Fold two paper towels and place on a plate. Put tofu on top of paper towels, and then fold two additional paper towels to place on top of the tofu. The tofu block will be sandwiched between the layers of paper towels. Next place a heavy pan on top of the tofu block. Then add a few heavy cans from your pantry to place inside the pan. Allow tofu to press for 20 minutes. If you have a tofu press, you can use that instead of following these steps.
While tofu is pressing, make the dressing. Drain cashews from boiling water. Add to high speed blender. Add lemon juice, white vinegar, dijon mustard, aquafaba, water, salt, pepper, and turmeric. Blend until smooth and cashew pieces are completely combined. If dressing is too thick add a tablespoon of water or aquafaba until you reach your desired consistency.
Dice onion and chop pressed tofu. Remove tofu from press. Chop tofu into small pieces. To do this I but the tofu into thin slices, then flip so that the short side of the tofu block is on the cutting board and make thin slices going the other direction. Then chop into small cubes.
Add chopped tofu to mixing bowl. Press a dry paper towel over top to soak up any remaining water. Add chopped onions, and pour dressing over top. Gently fold the dressing into the tofu. Careful not to stir too vigorously and break up the tofu chunks.
Serve on two pieces of whole wheat bread or bread of choice. Top with spinach, lettuce, and/or tomatoes. Slice in half and enjoy! This recipe makes 4 whole sandwiches.