Season chicken cubes with salt and pepper.
Heat olive oil in a large skillet over medium-high heat.
Add chicken to the skillet in a single layer and cook for 5-7 minutes until browned and cooked through.
Remove chicken from the skillet and set aside.
Add asparagus and minced garlic to the same skillet; sauté for 3-4 minutes until asparagus is tender-crisp.
Deglaze the skillet with chicken broth and lemon juice, scraping up any browned bits.
Return the chicken to the skillet and toss with red pepper flakes.
Cook for an additional 1-2 minutes until heated through and the sauce has reduced slightly.
Serve immediately.