Step 1

In a large pot or pressure cooker, saute the onions until they soften. Add the peppers and carrots and cook for another two minutes. Add the garlic and remaining vegetables and cook for another two minutes.

Step 2

For regular cooking: Add all remaining ingredients EXCEPT lettuce and salt. Bring to a boil, reduce the heat to a simmer, and cook, covered, for about 30 minutes, adding additional water or vegetable broth as needed to keep a soupy consistency. Just before serving, stir in the lettuce and salt.

Step 3

For pressure cooking: Add all remaining ingredients EXCEPT lettuce and salt. Lock the lid in place and bring to high pressure. Cook at high pressure for 6 minutes, remove from heat, and allow pressure to come down naturally. (If pressure is not down after 15 minutes, use a quick-release method.) Just before serving, stir in the lettuce and salt.

Step 4

For slow cooking: Place sauteed vegetables and all remaining ingredients EXCEPT lettuce and salt into slow cooker. Cook on low for 8 hours or high for 4-6 hours. Just before serving, stir in the lettuce and salt and add additional seasonings, if necessary.