Heat oven to 350ºF. Spray a 13x9-inch (3-quart) glass baking dish with cooking spray so the Southwest Nacho Casserole releases easily. In a 12-inch nonstick skillet, cook the lean ground beef over medium-high heat, stirring frequently and breaking it into crumbles, until thoroughly cooked and no longer pink; drain well to remove excess fat.

Stir in the water and the Old El Pasoᵀᴹ Smart Fiestaᵀᴹ Reduced Sodium Taco Seasoning Mix until the beef is evenly coated. Bring the mixture to a boil; cook 2 to 4 minutes, stirring occasionally, until thickened. Stir in the Old El Pasoᵀᴹ chopped green chilies so they are evenly distributed throughout the beef mixture.

Spread the Old El Pasoᵀᴹ refried beans evenly in the prepared baking dish, creating a smooth layer. Spoon the hot ground beef and green chile mixture over the beans and spread it into an even layer. Cover the baking dish tightly with foil to keep in the moisture and heat.

Bake the covered casserole 30 to 40 minutes or until bubbly around edges and the layers are heated through and piping hot.

Remove from oven. Carefully uncover, watching for hot steam. Sprinkle the shredded reduced-fat cheddar cheese evenly over the hot casserole, then top with the chopped tomato, chopped green onions and sliced ripe olives. Arrange 18 to 20 yellow corn tortilla chips (extra thick if possible) around the outside edges of the baking dish. Return to oven; bake uncovered about 10 minutes longer or until cheese is melted and the toppings are heated through. If desired, top with dollops of sour cream. Serve immediately with the remaining yellow corn tortilla chips for scooping.