In a large saucepan cook frozen vegetables and, if desired, jalapeno pepper in hot butter for 3 to 5 minutes or until tender. Stir in flour. Stir in milk and half-and-half. Cook and stir until slightly thickened and bubbly. Cook and stir for 2 minutes more.
Stir in thawed hash brown potatoes, salmon, parsley, lemon juice, salt, and black pepper. Cook and stir until heated through.