Heat cooking fat in a 12-inch skillet over medium-high heat.
Add minced garlic and cook until browned (~2 minutes). Add chicken, basil, salt, and pepper; cook for 12-15 minutes until cooked through. Transfer chicken to a plate.
In a small bowl, mix chicken stock, balsamic vinegar, and tapioca starch.
Cook pears in the same skillet for 4-5 minutes until browned. Add balsamic mixture; bring to a boil and cook 1 minute.
Reduce heat to low, return chicken to skillet, and heat through. Add lemon juice and spinach; cook until spinach wilts.
Notes
Use fresh basil for best flavor and adjust seasoning to taste.