Heat the olive oil in a large stockpot and add the vegetables, herbs, and garlic. Saute over medium heat, stirring occasionally, until the vegetables are golden. Stir in the tomato paste and cook for 1 minute longer. Add the chicken bones, then pour in enough cold water to cover, about 8 cups. Season lightly with salt and pepper. Bring to a boil, skimming off any scum that rises to the surface. Reduce the heat and let simmer gently for 1 hour.

Let the stock stand for a few minutes to cool slightly and allow the ingredients to settle before straining through a fine sieve. Cool and refrigerate, or freeze in convenient portions. Use up fresh stock within 5 days or keep frozen for up to 3 months.