This classic Mexican red salsa (the name translates literally to mean "red sauce") takes little time to make and produces a fresh, versatile salsa that goes great with tortilla chips, grilled steaks, tacos, scrambled eggs, burrito bowls, avocado toast, and more. Yield: Approx 2 quart of salsa. (That's a lot of salsa.)
Preheat oven to broil with an oven rack on the top rack. Line a sheet tray with aluminum foil.
Cut onion into quarters. Cut red bell pepper, poblano pepper, and serrano peppers in half, remove seeds and ribs. Optional: Leave the seeds and ribs on some/all of the hot peppers for a spicier salsa.
Place the tomatoes, whole, stem-side down on the sheet tray. Cut the peppers in half and arrange them cut-side down, skin-side up. Cut the onion into quarters, slicing through the stem end and arrange them skin-side down (but remove the skins).Roast the veggies under the broiler on the top oven rack for 10-15 minutes. The skin of vegetables should be deeply browned in spots, but not burned.
Place all the roasted veggies, plus garlic cloves and salt in a blender or food processor and process until desired consistency has been reached. For a chunkier salsa, run on low speed for a shorter amount of time. For a more sauce-like salsa, run on high speed for a longer amount of time. Adjust salt to taste.
Serve warm or cold.
To freeze: Put the portion you plan to freeze in a saucepan over medium heat and let it simmer until it thickens slightly and some of the liquid has evaporated. Let it come to room temp before you freeze it. Make sure to leave ½" of air at the top of the container, because the salsa will expand as it freezes.
If you don't have a broiler setting on your oven, crank the heat as high as it goes and use the top-most rack. OR use a propane/culinary torch OR grill the veggies.
Alternate instructions: Roast the peppers and onions under the broiler. Pulverize with the raw tomatoes and garlic in the blender. Then transfer that mixture to a sauce pot, bring to a low boil, then reduce temp and let simmer for 20-30 minutes. This can help intensify the flavors in the salsa, but also creates one additional dish to wash.