How do you make tomato paste?
Tomato paste is just tomatoes with the water removed, essentially.  I'd slice the tomatoes in half and roast them (cut side up) at 350 degrees F for an hour (this will concentrate the flavour nicely and you can add s&amp;p/olive oil/herbs/garlic if you want).  Then mash them through a sieve or food mill to get a smooth consistency.  Then put that tomato puree in a pot and just boil them down until it's as thick as you want.  As it gets thicker, you'll need to stir it regularly to prevent it sticking to the bottom of the pot and burning.