FOR SAUCE: In 3-quart saucepan over medium heat, bring tomatoes, tomato paste, dried oregano, salt and chipotle chile to a boil. Reduce heat and simmer uncovered for 10 minutes. If desired, with potato masher, crush tomatoes to form sauce. Stir in basil.
In large bowl, combine all slider ingredients: Mix well. Shape into patties 2 to 2½ inches in diameter. This can be measured using an ice cream scoop with mixture slightly rounded.
In large skillet or Dutch oven, brown patties in batches over medium-high heat, remove cooked patties to slow cooker on low setting. Pour sauce over patties. Cook for 1½ to 2 hours. Serve on small round buns(dollar buns).