Asparagus and Red Pepper with Balsamic Vinegar

Ingredients

• 1 tablespoon butter
• 1 tablespoon olive oil
• 1/2 bunch fresh asparagus, trimmed
• 1 red onion, sliced
• 1 red bell pepper, sliced
• salt to taste
• 1 tablespoon balsamic vinegar
• 1/4 cup Parmesan cheese
• 1 tablespoon sesame seeds (optional)
• 1 tablespoon toasted pine nuts (optional)