Make the basil tahini: in a food processor, combine the tahini, olive oil, garlic, lemon juice, basil, salt and pepper. Pulse the machine until the basil is finely chopped and incorporated. With the motor running, drizzle the cold water into the feed tube until you have a creamy but still loose consistency, similar to table cream. Add more water if necessary and check the basil tahini for seasoning. Adjust and set aside.

Cook the pasta according to package directions. Reserve 1 cup of the salted and starchy cooking water. Drain the pasta and set aside.

Heat 2 teaspoons of the olive oil a large, deep skillet (or braiser) over medium heat. Add the tomatoes to the skillet and stir. Keep stirring the tomatoes until they are lightly browned, glistening, and starting to burst. You will have to use the back of your spoon to get this process going. I find this takes a good 8-10 minutes total. Scrape the burst tomatoes out into a bowl and give the skillet a good wipe

Return the skillet to the heat with the remaining olive oil. Add the mushrooms to the skillet and let them sit for a full 2 minutes. Then, stir the mushrooms and season them with pepper. Let them sit another full minute. Then start stirring them again. They should be lightly browned and glistening. Season the mushrooms with salt. Continue letting them cook until evenly browned, soft, and glistening.

Add the pasta to the skillet along with the basil tahini. Stir everything up until evenly combined and warmed through. Season the pasta with salt and pepper and stir. If the pasta seems a little dry, add some of the reserved pasta water until you reach your desired consistency. Transfer the pasta to your serving vessel and scatter the burst tomatoes on top along with the extra basil and red pepper flakes. Serve and enjoy immediately.