In large kettle soak beans in cold water to cover by 2 inches overnight

Drain beans in a colander and return to kettle with cold water to cover by 2 inches

Cook beans at a bare simmer until tender, about 1 hour, and drain in colander

In a skillet cook onion in 2 tablespoons butter over moderate heat until softened

In a 6 to 8 quart heavy kettle melt remaining 6 tablespoons butter over moderately low heat and whisk in flour

Cook roux, whisking constantly, 3 minutes

Stir in onion and gradually add broth and half-and-half, whisking constantly

Bring mixture to a boil and simmer, stirring occasionally 5min or until thickened

Stir in Tabasco, and Monterey Jack and cook mixture over moderately low heat, stirring 20min

Stir sour cream into chili

Garnish chili with coriander and serve with salsa