Pressure Cooker Vegetable Stock - cooking recipe

Ingredients

2 tablespoons olive oil
4 medium onions (diced)
5 celery ribs (diced)
3 garlic cloves (minced)
3 large carrots (diced)
6 sprigs rosemary
10 sprigs thyme
1 teaspoon salt
fresh ground pepper
20 peppercorns
2 cups cauliflower (diced) (optional)
2 cups green beans (sliced) (optional)

Preparation

Saute the garlic, onions and celery gently in the olive oil in the bottom of the pressure cooker.
Add all the rest of the ingredients and fill with water until it it 3/4 full. It's important not to fill your pressure cooker more than 3/4 full for safe cooking.
Seal,Bring up to pressure and cook for 40 minutes.
Turn off the heat and let the pressure drop naturally. Strain the liquid though a sieve into a large pot, press as much liquid out of the vegetables as you can, discard the vegetables.
Once cool freeze the liquid for use in vegetarian soups, sauces, lasagne etc.