Bring a large pot of salted water to a boil. Cook the bucatini (or pasta of your choice) until al dente. Follow the box instructions.
While your water comes to a boil, make the creamy mushroom sauce according to the recipe.
Once the pasta is al dente, transfer it to the skillet with the creamy mushroom sauce using pronged spoon or spaghetti rake. You will bring some pasta water along with the bucatini and that's fine! It will slightly thin the sauce out and help it stick to the pasta. Just make sure you let any excess water drip off the pasta for a few seconds before you transfer it and put it into the sauce (even when you let the excess water drip off, you still bring a little pasta water into the sauce.)
On low heat, delicately toss the bucatini into the mushroom sauce, until it's fully coated and looks glossy and saucy. Plate the pasta and set aside. Feel free to cover the pasta with foil to keep it as warm as possible and prevent oxidization. Not necessary but always welcome!
Heat a skillet over high heat (the highest of the high!) After 1-2 minutes, test if the skillet is hot enough by splashing a little bit of water onto the surface. If the water evaporates and bubbles, the skillet is not hot enough. If the water beads up andd bounces on the surface, your skillet is good to go! Pour the water out of the skillet into the sink.
Thoroughly dry off the scallops with a paper towel and season with salt on both sides. Make sure they are as dry as possible before moving on to the next step.
Season the skillet with 1 tbsp of vegetable oil. It will be shimmering immediately and start lightly smoking.
Immediately place the scallops around the rim of the pan, where the oil pools up. Fun fact: the edges of the pan (where the oil settles) are hotter than the center. Space the scallops out accordingly and do not overcrowd the pan. If necessary, you can make them in two batches! It only takes 2 minutes.
Do not touch the scallops for 1-2 minutes. (For smaller scallops this will be closer to 1 minute, for larger scallops this will be closer to 2 minutes.) When you see a strong golden brown ring forming around the scallop, lightly lift it with a spatula to see if it's perfectly golden brown. Do not lift the scallop if the golden brown rim is only faint golden brown or light golden in color.
Once the scallops are golden brown to perfection, flip them and let them sear another minute.
Move the scallops to one side of the skillet and then add 2 tbsp of butter on the empty side of the pan, opposite of the scallops. As it melts, use a spoon to pour the melted butter onto the scallops as they finish searing. This is called basting. You're basically just keeping the scallops juicy, while adding a ton of flavor, as they finish searing! Because the butter gets so hot, it naturally browns and gets toasty. That's why browned butter scallops are a *~thing~*
Plate them onto the pasta immediately and finish off the dish with a little bit of Parmesan cheese and a lot of fresh parsley. Serve immediately!