Heat olive oil in a large skillet over medium heat. Add asparagus, stirring until crisp-tender, about 3-5 minutes. Transfer to a plate.

In the same skillet, add butter and let it melt. Season chicken with salt and pepper, and cook until golden brown, about 3-5 minutes per side. Remove and set aside.

Add garlic and red pepper flakes to the skillet. Stir quickly for about 1 minute until garlic turns light golden.

Pour in chicken broth and scrape up bits from the pan. Bring to a boil, then simmer for about 5 minutes to thicken.

Stir in lemon juice, zest, and dill. Return chicken and asparagus to the skillet and cook for an additional 2-3 minutes.

Serve immediately with your choice of rice, pasta, or bread.