Asparagus and Red Pepper with Balsamic Vinegar

1 tablespoon butter

1 tablespoon olive oil

½ bunch fresh asparagus, trimmed

1 red onion, sliced

1 red bell pepper, sliced

salt to taste

1 tablespoon balsamic vinegar

¼ cup Parmesan cheese

1 tablespoon sesame seeds

1 tablespoon toasted pine nuts

Melt the butter with the olive oil in a large skillet over medium heat; add the asparagus and red onion in the mixture, season with salt, and cook until the onion begins to soften, about 5 minutes. Stir the red bell pepper into the mixture and continue cooking until the onions begin to caramelize, another 5 minutes. Remove from heat and add the vinegar, Parmesan cheese, sesame seeds, and pine nuts; toss to combine.