Prep to be done at home before leaving: Peel, wash, and cube potatoes into 1 inch cubes. Store in Zip lock bag with water and a little lemon juice to prevent oxidization. Also, halve and thin slice the onion,
storing in Ziploc bag. Pour both cans of tomatoes in a bag for easy access at game. Do not drain tomatoes.
At game, turn side burner on grill to medium and heat skillet with
oil in it
When oil is hot, add onions and caramelize with salt and pepper
When onions are caramel colored, add undrained tomatoes, potatoes, and 1/2 cup water
Cover and simmer on medium heat for 30 minutes or until potatoes are soft and all liquids are cooked off. Stir every 5-10 minutes and if all liquids cook off before the potatoes are soft, add more water to prevent burning.
When potatoes are almost done, heat the grill to low and warm the
tortillas directly grate until grill marks are on the tortillas. Fill with
mixture and add a dollop of sour cream on top.