1. Preheat oven to 375 degrees F. Lightly butter an 8-cup souffle dish; set aside.

2. In a medium saucepan over medium heat, melt butter. Whisk in flour until mixture is smooth. Whisk in milk.

3. Whisk sauce over medium-high heat until it boils and thickens. Remove pan from heat.

4. Add cheese, salsa, and salt; stir until cheese melts. Beat in egg yolks.

5. In large bowl of electric mixer, beat egg whites until they hold soft, moist peaks. Stir one fourth of whites into cheese mixture to lighten it; fold in remaining whites.

6. Pour mixture into prepared souffle dish and bake in preheated oven 30 to 40 minutes.

* Timesaver Tip: To make ahead: Prepare recipe through step 4. Cover surface of mixture with wax paper and refrigerate up to 24 hours. Put egg whites in a bowl, cover, and refrigerate. To complete dish, bring cheese mixture and egg whites to room temperature (this can be done quickly in a microwave oven at a low setting) and continue with steps 5 and 6. (Refrigeration is not necessary if recipe is prepared only a few hours in advance.) To make ahead and freeze: Prepare recipe through step 5. Wrap freezer-to-oven souffle dish in aluminum foil. Label, date, and freeze up to 2 months. To serve, preheat oven to 375 degrees F. Remove foil and put souffle dish directly into oven from freezer; do not thaw. Bake 50 to 55 minutes. Souffle will be puffy and the top well browned. Serve immediately.