Chop your mushrooms and veggies, and crumble your tempeh. We're making things easier on ourselves by using "mis en place" (prepping our ingredients before we begin cooking).
Put the olive oil, mushrooms, onion, carrot, celery, and garlic in a cast iron skillet. Heat them over medium heat on the stove top for about 10 minutes, stirring frequently. They should soften but not brown.
Add the crumbled tempeh and soy sauce to the skillet. Stir and let the tempeh brown in the skillet for 5-10 minutes.
Next, add the crushed tomatoes, dried parsley, dried oregano, dried basil, salt, and black pepper. Turn the heat down to medium-low and let the sauce gently simmer, stirring occasionally.
To serve: Plate your spaghetti squash or pasta. Add the vegan Bolognese, and top with your preferred toppings. I used about 4 teaspoons of fresh basil and 4 teaspoons of freshly grated Parmesan cheese per plate. Enjoy!