In a hot skillet, add the tomatoes, garlic, and the coconut oil. Cover it and let it simmer and steam for 10 minutes on medium high. When the tomatoes are soggy, chop them with a knife while they are in the pan. They will cut very easy when they are soft and ready, and may even be able to cut with a fork. When they leak water, that will be the time to crush and cut them in halves. Cover the pan again.
Add the arugula and basil and let that stew for 5 minutes, moving it around. If you are making pasta, add a ladleful or 2 of the finished pasta water.
Do not strain the pasta through a strainer, use a spoon that the water can leak through or cover the lid and tip the pan, draining all the water out the side. You'll want to keep a bit of the moisture in the pasta, which these methods will do. Add the pasta to the skillet and toss.