Wash the collard greens thoroughly, several times if necessary
Wash the sweet potatoes and prick each one 8 times with a fork
Cook the sweet potato in the microwave ( on a microwave safe plate) on high for 4 minutes. Turn them over and cook for another 3-4 minutes until they are tender. Cooking times will vary depending on how thick the sweet potatoes are.
Let them cool enough to handle.
Remove the tough part of the stem
Stack the collard leaves and roll them up ( you may have to do this in batches) slice the collards into 1/2 inch lengths.
Slice the onion into 1/4 inch slices
In a large pot saute the onion in 1 tablespoon of oil on medium/low heat, stirring occasionally, until they begin to soften and brown.
Slice the pepper and cook with the onion for 5 minutes
Slice the garlic and stir into the onions, cook for about a minute or less
Add the sliced collard greens, tomato,1 tablespoon red wine vinegar and vegetable base and water (or vegetable broth) and stir
Cover and cook on medium low heat for 20 minutes stirring occasionally.
Remove the lid and cook uncovered for 5 minutes to reduce the liquid in the pot. Add more red wine vinegar, 1 teaspoon at a time, if you like
Cut each sweet potato into quarters lengthwise
Heat 1 tablespoon of canola oil in a skillet and cook the sweet potato wedges until they are brown on each side
Serve 2 sweet potato wedges per person over collard greens