Boil mushrooms in 4 cups water for 5 minutes. Let them soak in the hot water for a few minutes while you cook the lentils, until the liquid is dark brown and has cooled off a bit.Meanwhile, bring lentils to a boil in vegetable broth. Reduce to a simmer, then cook for about 15 minutes or until just tender. Drain. Remove the soaked mushrooms with a slotted spoon and rinse them under cool running water to remove any excess residue. Chop up the soaked mushrooms, then rinse them once again (there can be stubborn debris that clings, multiple rinses are the best way to remove any residual dirt). Reserve the chopped mushrooms.
Line a handheld mesh strainer with a coffee filter. Strain the mushroom cooking liquid through a coffee filter into a bowl or measuring cup. This may take a few minutes and a bit of maneuvering. I find I have to swirl the liquid around a bit for it to go through the filter, and often I need to replace the filter a couple of times in order to get all of the liquid to go through. While this takes some effort, the liquid often contains a bit of dirt residue from the harvested mushrooms. Straining it out allows us to use this very flavorful liquid in the finished product. Reserve the strained liquid.
In a large 5 quart sauté pan or sauce pot, heat 2 tbsp extra virgin olive oil over medium. Sauté diced onion for 10-15 minutes until soft, translucent and starting to turn golden.
Add the fire roasted tomatoes to the pot along with the cooked lentils, soaked diced mushrooms, ¼ cup freshly chopped parsley and remaining spices. Stir. Cook the mixture 10-15 minutes longer until the lentils are fully tender, the excess liquid has reduced, and the sauce is thick.
Serve sauce over pasta as a vegan alternative to Bolognese, or you can enjoy this on its own as a flavorful lentil stew. Garnish with remaining 1 tbsp parsley.