Preheat oven to 300 degrees. Grease 1 1/2 quart souffle dish. Line bottom with wax paper. Beat cream cheese and cheddar cheese in large bowl with an electric mixer till light and fluffy. Beat in eggs one at a time. Mix in mustard and salt, then pour into dish. Put in oven. Bake until you can stick a knife in and it comes out clean, about 1 hour. Let cool in shut off oven for 30 minutes. Remove from oven, cover and refrigerate until cold. Remove from souffle dish and invert onto serving plate. Pour salsa over top. Garnish and serve with crackers