wash & halve the tomatoes, taking out the green stem connector on both halves putting a cross cut in the round side
Around now turn on the oven to 150°C fan so it's ready when the tomatoes are ready.
Oil the trays, and arrange the tomato halves as close as possible
make a cross cut in the top of each half tomato with a serrated knife.
brush each tomato generously with olive oil.
put the filled trays in the oven and leave to start cooking. We'll lower the temperature after a bit.
Cut the onions in half top to root. Cut off both ends and remove peel.
Cut roughly into 4 (or 9 pieces if you wish) and place in food processor & pulse blitz until reasonably well chopped. You can dice finely by hand but it's a lot easier to blitz chop them in the food processor if you have one. Don't over do it though - they want to be fairly small pieces but not mush.
After the first batch put the large pan on with a nice amount of extra virgin olive oil on a low heat,
put the first batch in the bowl while you do the second batch of onions, then tip the whole lot in the pan and give it a good stir round. Turn up the heat so it's a low medium. Make sure to stir it every few minutes - it will take around 30 - 40 minutes to get them nice and soft and a little brown. It works best to cover it for say the first 10 minutes to keep the heat in, then remove the lid so the water get's driven off - if you do they won't brown properly. As the cooking goes on make sure to adjust by lowering the heat to stop them sticking & burning.
While the onions are cooking, you can sort the garlic out. Peel all the cloves and either use a garlic press - or cheat like I do with a kitchen aid mini grinder - much quicker and easier. Add to the onions in the pan - when done - after around 5 to 10 minutes.
Next tackle the fresh ginger - cut off any manky bits and either chop finely or blitz in a kitchen aid mini grinder and add to the pan with the onions
Check the slowly roasting tomatoes - it should be around 30 minutes and they should be looking like they are pretty soft and cooked - but not really brown at all. You can turn the oven down to 125°C of leave it at 150°C but you'll need to keep a close eye on it so the don't burn. You'll definitley need to turn them down after an hour or so. Total cooking time is around 2 hours.
As the onions come to a nicely browning stage add the cummin and chilli and mix in well - allow to cook for a few minutes longer to develop the flavour - but don't let it burn. Once done - tip out into the large bowl.
Once the tomatoes are nice and brown and really well roasted, but not burnt, remove from the oven and put in the large pan - no need to wash it - just chuck them in and then give them a reasonable blend with a stick blender. You're not try to make a puree, but they need to be fairly well broken up.
Once that's done, you can add the onions back in and all the other bits: tomato puree, cans of tomatoes, crumbled stock cubes, soy sauce, water, & of course the lentils!
Then bring to the boil. Once boiling, you can either simmer it on a very low heat, or put back in the oven on 125°C heat and cook on for around 45 minutes to an hour. The lentils need to be quite soft, but not too broken up.
Eat some now, and portion up the rest into 325g lots in plastic take-away containers or similar and freeze. Makes around 22 portions.