Halve plum tomatoes or cut large tomatoes into thick slices.
Put into a large bowl, and toss with 1 tablespoon olive oil and ¼ teaspoon salt.
Lay out in a single layer on a foil-lined sheet pan and roast for 35-40 minutes, until tomatoes are softened and starting to brown around the edges.
Meanwhile, toast pine nuts in a small nonstick skillet over medium-low heat, stirring frequently.
Watch carefully, as pine nuts turn quickly from toasted to burned. Let cool.
Scrape roasted tomatoes into food processor.
Add in cooled toasted pine nuts, basil, remaining salt, parmesan cheese, remaining olive oil, and garlic clove.
Blend until smooth, scraping down the sides as needed. If you want a looser pesto, feel free to add more olive oil.
Notes
Storage Tips: Store leftover tomato pesto in an airtight container in the refrigerator for up to 5 days. To make sure the color stays fresh, try drizzling a little bit of olive oil over the top. You can also freeze pesto in a freezer-safe container for up to 3 months. Try storing in ice cube trays so that you can pop out a cube whenever you need one. Great for adding flavor to soups!Expert Tips: Use the ripest tomatoes you can find—they’ll give you the best flavor and color for this red pesto. If you don’t have super ripe tomatoes, try adding in a few sun-dried tomatoes for extra depth of flavor. This is particularly helpful in the winter months when tomatoes are at their worst!Don’t blend for too long. You want a bit of nutty texture in your pesto, and some little specks of green from the basil are very pretty. If you blend for too long, the color will wash out a bit from blending the green into the red tomatoes. If you’re making tomato pesto pasta with this recipe, be sure to save some pasta cooking liquid before you drain the pasta. Then toss the pasta with the pesto, stirring in some of the reserved pasta water to make a smooth sauce.