Zesty Beef and Rice

Ingredients

• 1 lb lean ground beef
• 1 medium onion, chopped
• 1 green bell pepper, chopped
• 2 12 cups cooked rice
• 1 (15 ounce) can whole kernel corn, drained
• 1 (15 ounce) can Mexican-style tomatoes
• 1 (15 ounce) can diced tomatoes
• 1 tablespoon chili powder
• 1 teaspoon garlic powder
• 1 teaspoon salt
• 1 (8 ounce) packagecubed Velveeta cheese
• 1 cup crumbled butter flavored cracker
• 12 cup chopped walnuts or 12 cup pecans
• 2 tablespoons margarine, melted