Preheat your oven to 400'F. Chop all of your veggies into medium sized chunks. You want them to be roughly the same size. Toss them in a large bowl with the tomato paste and olive oil.
Lay the vegetables flat on a sheet tray and roast in the oven for 30 minutes, turning half way through.
After roasting, scoop the veggies into a large stock pot. Pour the water over top and turn the heat to medium high. Allow the stock to come a boil, then reduce to a medium low. Simmer the mixture with the peppercorns, salt, and parsley until reduced by half.
Once reduced, strain the stock through cheese cloth into a large bowl. You should be left with a clear liquid that isn't cloudy. You can save this for up to 2 weeks refrigerated and 1 year frozen.