This couldn't be easier -- just add everything except the scallions, polenta, butter and oil into the crock pot and cook on low 8-10 hours. At the end of cooking, make sure you taste for any additional seasoning.
Polenta -- There are many flavors of polenta all very unique these days. Cheese, herb, plain, sundried, onion, you name it. You can use whatever you like. I happen to like the plain best, but don't be afraid to try something else.
In a medium sauce pan add the olive oil and butter and bring to medium high heat. Add the polenta slices and saute until lightly golden brown. Flip and saute the other side until golden brown as well.
Serve -- Plate the polenta and top with the ragu over top. Garnish with the scallions and Monterey Jack cheese. serve with a nice salad for an easy dinner.
NOTE: Chipoltes are spicy. Start out with 1-2 small chipoltes.You could add a little more half way through cooking for a little more heat, but go easy.