In a heavy skillet brown the meat along with the onion and green pepper. Add the tomatoes, tomato paste, ketchup, powdered mustard, chili powder, molasses, vinegar, salt and pepper. Simmer for 5-10 minutes adding a little water if id gets too dry. Of course you can stop right here and serve this over hamburger rolls.
Meanwhile, preheat the oven to 425 degrees. Grease a 9"x13" pan. Open on of the tubes of crescent rolls and press the seems together to make a large rectangle. Lay in the bottom of prepared pan. Spoon meat mixture on top. Sprinkle with shredded cheese.
Open the second tube of crescent rolls and press seams together. Place on top of cheese. Brush with milk and sprinkle with sesame seeds. Bake for 15-20 minutes. Cut into squares to serve.