Heat 2 tablespoons of the olive oil in a medium sauté pan over medium heat. When hot, add the mushrooms, carrots, celery, onion, and garlic. Add a good pinch of kosher salt and a little fresh ground pepper. (It will seem like a lot of mushrooms, but don’t worry—they cook down a lot.) Cook for 8-10 minutes until the vegetables are soft and the mushrooms have released all of their liquid.
Stir in the tomato paste and cook for 2 more minutes (to cook off the bitterness in the paste).
Stir in the crushed tomatoes, oregano, crushed red pepper (if using), and basil. Simmer gently for 15 minutes until the sauce has thickened and the flavors have combined. Taste and season with a little extra salt if necessary.
While the sauce is simmering, spiralize your zucchini with the blade that makes spaghetti-size strands. (The noodles will be verrrrrry long, so I like to trim them into shorter strands with kitchen scissors.)
Heat the remaining tablespoon of olive oil in your largest skillet or sauté pan. When its good and hot add the zucchini noodles. Season with salt and pepper and cook, tossing regularly with tongs for 2 minutes until just tender. Immediately remove the zucchini noodles from the pan. (You need to get these out of the pan quickly, peeps. Overcooking them will make them watery and gross.)
Divide the zucchini noodles among 4 bowls and top with a generous amount of Bolognese. Garnish with freshly chopped basil and serve immediately. Feel free to get some grated Parmesan involved if you like.