Add vegetables and this doubles as a perfectly good summer soup. I use asparagus stock here because this sauce is going to accompany my Asparagus Paella, but feel free to replace it with basic stock.
Recipe adapted from Dirt Candy: A Cookbook by Amanda Cohen, Ryan Dunlavey, and Grady Hendrix (Clarkson Potter, 2012).
In a medium-sized pot, heat the olive oil to medium-high and sweat the onion and garlic. When the garlic is very soft, add the saffron and cook, stirring, for 2 minutes. Increase the heat to medium, and add the tomato and salt. Cook, stirring occasionally, until the tomatoes start to break down, about 10 minutes. Add the seaweed and stock. Bring to a simmer, turn the heat to low, and cook for 30 minutes. Remove from heat and let cool slightly.
Working in batches, puree the mixture in a blender until smooth. Push through a chinois, or fine mesh strainer, to make it silky. The sauce will keep covered in the fridge for up to a week.