Remove scallops from their packaging, pat dry. Set them aside to let them come to room temperature while preparing the noodle salad.
Prepare the rice noodles according to the package directions.
Place the shredded carrots and sliced red onions in a large bowl; set aside.
In another medium bowl, whisk together the rice vinegar, 1/2 cup olive oil, ginger, garlic, hot sesame oil, sugar, and kosher salt. Set aside.
Season scallops on both sides with kosher salt and pepper.
Heat a cast iron skillet (or other heavy-bottomed, oven-proof skillet) over high heat. When skillet is hot, add just enough oil to cover the bottom of the skillet; give it a swirl to ensure even coating.
Add seasoned scallops to the skillet and sear on one side until nicely browned, about 1-2 minutes (depending on how hot your skillet is).
Turn scallops over; turn off the burner.
Place skillet in the oven and finish cooking, 1-3 minutes, or until scallops feel firm to the touch. (They will cook fast!)
To assemble, add the cooked rice noodles to the carrots and red onion. Pour the dressing mixture over the top and toss.
To serve, place a portion of the rice noodle mixture on each plate.
Top each plate of rice noodles with three scallops.