The above recipes for salsa, as fine as they are, are all for raw
salsas. This is The Real Thing
Thoroughly clean a bunch of tomatillos and an equal amount of Roma tomatoes. Nip out the hard bits but do not core peel slice etc. The exact amount is determined by the size of your pan. I use a 10X2" Revereware pan, and use enough tomatoes and tomatillos that the next step has to be done twice. That's as close as I can get on the amounts, it's an intuitive thing.
Sear the tomatos and tomatillos over high heat. Keep them moving, they will get black sear marks. The trick is to sear the skins without charring them.
Remove tomatoes, add a little vegetable oil, a bunch of chopped fresh cilantro, a little lime juice, one medium-to-large sweet red onion, quartered and sliced, and 3-7 sliced serrano peppers, the little green/yellow/red ones. Slice 'em in rings, include the seeds if you want it a little hotter. Saute medium-hi heat stirring constantly
until onions are nicely transparent. Add one good *glurg* of decent tequila, flame off alcohol with a match. If it doesn't flame add another shot. If it still doesn't flame the pan wasn't hot enough, or you are using cheap tequila. Go invest in a bottle of Cuervo Gold. (If you skip this step you don't have my salsa, you've got spicy tomato sauce.)
After the flames are gone add the tomatillos and tomatoes, one at a time, whole. Crush them with your wooden spoon. If you want to slice them first you can, it won't hurt the taste but might alter the texture. Cover and cook over low-medium heat, stirring occasionally, for no less than 30 minutes, until the texture is right. Right being your definition, I like it thick but with some of the ingredients still discrete.
Serve hot. If you want any for tomorrow separate it out and
refrigerate in a container marked "Last Week's Table Scraps For Compost" or "Mold Experiment, do not disturb". I've never had a batch last long enough to find out if it will go bad in the fridge, and we're mighty picky about our fresh food in these here parts, When in doubt Throw it out and all that jazz.