Step 1

Preheat the oven to 425°F/218°C

Step 2

Be sure the onions and tomatoes are cut into evenly sized pieces. Add the tomatoes, garlic, and onion to a mixing bowl or food storage bag. Add the olive oil and, season with salt & pepper, and toss to coat.

Step 3

Transfer to a sheet pan with a raised 1-inch lip and spread evenly over the pan.

Step 4

Roast for 30 to 35 minutes or until soft. Drain any excessive liquid from the pan and set it aside.

Step 5

Add the roasted vegetables to a blender or food processor and puree until it reaches desired consistency. If it's too thick add some of the reserved liquid or water to thin it out.

Step 6

Mix in the chopped herbs, taste for seasoning, and add salt as needed before serving.