Get your hands on a big pot. No, a *big* pot. At least twice as big as that one. Yeah, okay, that one might work, in a pinch.
Take four 28-oz/796-ml cans of whole roma tomatoes. Chop each of them a little, but leave chunks. Put the chopped tomatoes and all of the juices in the big pot. (Use fresh if you're more ambitious or have a lot of tomatoes.)
Take eight medium-to-large, very ripe mangoes (note to the locals: they're currently FIVE DOLLARS for a whole BOX at Save-on-Foods). Chop them into small chunks (to cut up a mango, I always slice two large pieces off on either side of the pit, chop up those parts first and discarding the peel, and then cutting as much as I can off of the pit. for the best way to get at the flesh on the big pieces, score it and then cut off chunks, like, um,
this). While doing this, save as much of the juice as you can -- though if they're ripe enough, this should be difficult. Put the pieces and the juices into the pot and give the mixture a stir. You should have approximately half tomatoes and half mangoes, in a thickish liquid.
Take a few very ripe avocadoes (I used three, but if I did it again I'd probably use one or two more). Cut them in half, discarding the pits. Squeeeeeze the flesh of the avocadoes out of their skins and into the pot, leaving a few chunks, but mostly making sure it turns into a squishy green mass. (Mm, appetizing.) Stir into tomato-mango mixture.
Add lots of herbs, whatever sounds good (I used cilantro, sage, rosemary, thyme, marjoram, basil, and oregano). Fresh from the garden is best. And I mean *lots* -- think "just enough to leave the plants still alive". Chop thoroughly with a sharp knife or in a food processor. Add to the pot.
Cook the contents of the pot on medium heat for ... well, as long as you want. At least a half hour, or enough time to let the herbs flow into the sauce. Do this while doing the next step.
Peel and chop a large, sweet red onion and a whole head of garlic. Sautée a little in two tablespoons of olive oil. When thoroughly cooked through (about ten minutes), add to the pot and give the whole thing a stir.
Add freshly ground pepper and salt to taste (you don't need much of the latter!). Serve as a sauce for fish (especially denser fish like salmon or swordfish) or pasta. Freeze the rest, to heat up whenever you feel like a quick meal.