Intense Homemade Tomato Paste

1. Start the flavor base. Set a wide heavy-bottomed pot over medium heat. Add the olive oil and garlic. Cook for 30 to 60 seconds until fragrant, not browned. If the garlic starts to color, lower the heat. You are building flavor, not toast.
2. Add tomatoes and season. Pour in the canned tomatoes with their juices. Add salt, red pepper flakes, and bay leaf if using. Add the Parmesan rind if using. Use a spoon to break up the tomatoes a bit.
3. Simmer and reduce. Bring to a gentle simmer, then lower heat to maintain a steady, quiet bubble (you want small blips, not a rolling boil). Cook uncovered, stirring every 10 to 15 minutes at first. As it thickens, it will splatter like it is trying to redecorate your stove. Lower the heat, stir more often, and consider a splatter screen. Scrape the bottom and corners well to prevent scorching. This takes about 90 minutes, sometimes a bit longer depending on your pot width and your tomatoes.
4. Blend smooth. When the mixture is very thick and most liquid has cooked off, remove the bay leaf and Parmesan rind (if using). Blend with an immersion blender (or carefully transfer to a blender) until smooth. Hot tomato splashes are rude, so if using a blender: vent the lid, cover with a towel, and blend in batches. If you want it extra silky, push through a fine-mesh strainer, but it is optional.
5. Finish the reduction. Return to the pot and continue cooking on low, stirring frequently, until it is thick like soft paste and glossy. You should be able to drag a spoon through and see the bottom of the pot for a second before it fills in. The last 10 minutes can go from perfect to scorched quickly, so stay close and keep scraping. This usually takes another 30 to 45 minutes.
6. Optional intensify. Stir in the vinegar (and soy sauce or Worcestershire if using). Cook 2 to 3 minutes, then taste and adjust salt.
7. Cool and store. Let cool completely. Refrigerate with a thin olive oil layer on top, or freeze in tablespoon portions for maximum weeknight usefulness.

Bonus: Oven finish (less stirring)

After blending, spread the thick tomato mixture in a thin layer on a rimmed sheet pan and bake at 300°F (150°C) for 30 to 45 minutes, stirring about every 15 minutes, until paste-thick and glossy. The edges darken first, so pull the darker bits toward the center as you stir.