Preheat the oven to 450 degrees F. Line a baking sheet with parchment paper.
Drain the cooked lentils and spread them out on a clean dish towel. Blot them until they are as dry as possible. Transfer the dried lentils to the baking sheet. Toss the lentils with the 2 teaspoons of olive oil, smoked paprika, garlic powder, salt and pepper. Spread the coated lentils out in a single layer and roast for 5-7 minutes, or until slightly crisped up. Set aside.
Bring the oven temperature down to 350 degrees F.
Place an oven-safe, deep skillet over medium heat. Once it’s sufficiently heated it up, pour in the tablespoon of olive oil. Add the shallots to the skillet and stir. Keeping stirring and sautéeing the shallots until they are lightly caramelized, about 15 minutes. Pour in splashes of water if the pan starts drying out.
Once the shallots are lightly caramelized, transfer all of the mushrooms to the skillet and stir. Let the mushrooms sit for a full minute. Stir them up and season with ground black pepper. Again, let the mushrooms sit for another full minute before stirring them up again. At this point, they should be glistening and letting off moisture. Season the mushrooms with salt, and add the thyme and garlic to the skillet.
Keep sautéeing the mushrooms and shallots until mushrooms are quite soft and starting to brown a bit, about 3 more minutes. Pour the balsamic vinegar and the tamari into the skillet and stir. Turn off the heat.
Mix in the rinsed brown basmati rice and the vegetable stock. Sprinkle a few pinches of salt and pepper in and stir. Cover the skillet and transfer it to the oven.
Bake the mushroom brown rice bake for 1 hour and 15 minutes, or until most of the liquid has been absorbed and the rice has fattened up. I would start checking it around the 50 minute mark. At this point, if the rice appears to be undercooked with minimal moisture in the pan, just splash in a bit more vegetable stock.
While the mushroom brown rice bake is cooking in the oven, make the gremolata. In a small bowl, stir together the parsley, lemon zest, and garlic. Set aside.
Once the mushroom brown rice bake is finished in the oven, remove it and top with the crispy lentils and gremolata. Serve hot.