Set oven to 300 degrees. Drain and pour beans and corn in bottom of 2 qt. baking dish. Sprinkle with pepper. Using a 10" skillet, saute onion in butter until translucent. Remove from heat and blend in the sour cream, cream of celery soup, and cheddar cheese. Pour over top of vegetables. Smooth to edges of dish. Next, pour melted butter or margarine over the top and add the crushed crackers. Sprinkle almonds over the top. Bake uncovered for 45 mins.