Place the chicken breasts in the slow cooker. Add the chicken broth, lemon juice, lemon zest, minced garlic, olive oil, thyme, rosemary, salt, and pepper.
Cover and cook on low for 4 hours or until the chicken reaches an internal temperature of 165 degrees.
Stir in the asparagus pieces during the last 30 minutes of cooking so they stay tender but not mushy.
While the asparagus cooks, warm the cauliflower rice in a microwave or skillet until hot.
Shred or slice the chicken, then serve it over the cauliflower rice with the asparagus and sauce spooned on top.