Cut spaghetti squash in half and scoop out seeds. Place in microwave safe dish and cook for ½-20 minutes until done or cook spaghetti squash your favorite way (See link above for more detail on my favorite way). When spaghetti squash is done, shred into "noodles", place in a colander lined with paper towels and set aside.
While spaghetti squash is cooking, whisk together all ingredients for the sauce except for the water. After everything is mixed together, add the water, 1 tablespoon at a time and whisk together until smooth. Set sauce aside.
Prepare the tofu by pressing to remove the water. Slice the tofu lengthwise through the center (like a book), then slice into about 24 small rectangles. (See link above for more detailed instructions and photos on how I like to slice tofu)
Lay the slices of tofu on a paper towel and cover with another paper towel. Press with your hands to remove more water.
Heat 2 tablespoons of canola oil in a large sauté pan over medium high heat. When hot, add the tofu and cook until golden brown, about 2 minutes per side. Flip and continue to cook on all four sides until they are crispy and golden brown. Remove the tofu and set aside.
Heat 1 tablespoon of canola oil in the same pan. When hot, add the red bell peppers and quickly stir fry for a few minutes until they are starting to get a little seared and are softening. Add the tofu back into the pan and cook for a minute, just to get it hot again. Turn heat to low, pour in the peanut sauce, and quickly stir everything together, so that all the tofu and peppers are covered in sauce. Don't let it sit too long or the sauce will start to congeal.
Add the spaghetti squash "noodles" and toss to incorporate and fully cover in sauce. Remove from heat as soon as everything is mixed together. Serve right away over a bed of arugula.
Notes
*be sure to use gluten free soy sauce for gluten free!