Step 1Rinse beans with cold water in colander. Drain. Place beans in 2-quart saucepan and add 2 cups water. Bring to boil on stove top, then lower heat to simmer and cover. Cook until beans can be pierced with a fork and seem tender, about 45 minutes. Drain off liquid and set beans aside.
Step 2Beat eggs well in small bowl; set aside.
Step 3Put cornmeal in small bowl and pour in 1/2 cup cold water. Stir to moisten all bits of cornmeal. (This keeps cornmeal from lumping when you add it to boiling water.)
Step 4Bring 2 cups water to boil in 3-quart pot. Add salt to boiling water, then slowly add cornmeal. Reduce heat to medium and keep stirring constantly for 1 minute. It will look thick and yellow.
Step 5Add 2 tablespoons butter, beaten eggs, buttermilk, cheese and reserved beans to cornmeal mixture and beat until smooth.
Step 6Smear bottom and sides of 1 1/2-quart casserole with 1 tablespoon butter, then pour bean-cornmeal mixture into it. Bake 40 minutes at 400 degrees until spoon bread appears to have set up and only slightly jiggles when shaken. (Using a potholder so as not to get burned, hold side of casserole and give it a shake.) If it doesn't appear to have set enough, bake 5 more minutes, then check again. Remove from oven.
Step 7Spoon out individual portions of spoon bread and put on plates. Serve with salsa and sour cream.