Bring a large pot of salted boiling water to a boil.

Dice the onion very fine, and slice the garlic in very thin strips. Then, drain the liquid from the jar of sundried tomatoes and give them a rough chop.

Grab a sauce pan and a tbsp of extra virgin olive oil on medium heat. When the oil begins to shimmer, add the onion and saute for a minute or two until fragrant. Then, add the sundried tomatoes and garlic. Add the chili flakes if desired. Saute for a couple of minutes, and then add in the tomatoes.

Use a fork to gently mash the tomatoes and cook down for 10 or so minutes on a simmer.

Add the pasta to the boiling water and cook until soft.

Remove the sauce from the stove and either put in a blender or use an immersion blender to blend the sauce to a smooth consistency.

Add sauce back to medium low heat and fold in the butter to make a smooth creamy sauce. Salt to taste.

Remove the cooked pasta from the boiling water and add directly to your sauce. Fold the pasta into the sauce, and then once coated, you can plate the pasta.