Cook pasta according to the instructions given, then drain and set aside to cool. If possible, place in the fridge to chill.
Cover a plate with 1-2 paper towels and place the raw scallops on them. Let them rest for about 5 minutes, then thoroughly pat them dry with another paper towel. Add a pinch of sea salt & pepper to them on both the top and bottom.
Set a carbon steel skillet on medium high heat. Once hot, add avocado oil and place the scallops in the skillet, leaving adequate space in between them. Sear on each side for 1 -2 minutes, or until a golden sear appears on the scallop and it can be easily lifted off the skillet. If the scallop is sticking to the skillet, allow it to sear for a few more seconds before flipping over.
Once the scallops have cooked, if desired, remove the skillet from the heat and add 1 tablespoon of butter to the skillet. Repeatedly spoon the melted butter over the scallops to give them a golden color and crispy coating. Set aside on a plate (do NOT keep the scallops in the hot skillet).
In a large bowl or jar (or blender), add the ingredients for the pesto. Use an immersion blender to blend up all the ingredients OR use a blender.
Add the pasta and pesto to a large mixing bowl and fold to mix/coat well. Add the tomato and red onion and lightly toss together. Lastly, fold in the scallops and enjoy! Season to taste with sea salt & pepper.
Enjoy!