1 can chopped, crushed or whole tomato, OR 4 - 5 fresh tomatoes
olive or vegetable oil
3 cloves garlic (to taste)
3 stalks celery
red pepper flakes
salt and pepper
pasta (any kind)
Anything else you have on hand: carrots, zucchini, etc
Boil pasta. In bottom of saucepan, brown onions and garlic in oil on medium heat. Add celery and mushrooms, stir often for a few minutes. Add other vegetables too (in order from hardest to softest, the hard ones take longer to cook). Chop up tomato (or open can), pour in and add spices to taste. Stir often, uncovered. Use a little pasta water to thicken if needed.
Hard to give an exact time for this, as it takes as long as it does for the vegetables to cook, depending on what you're using. You can add ground meat or veggie ground round when you're frying the onions. Squares of firm tofu are also good at this stage, though you might want to start it before the onions as it takes a long time to cook through.