In a small saucepan, combine the broth, lemon juice and flour. Bring to a boil, stirring constantly. Lower the heat and simmer until thick, about 3 minutes. Whisk in the butter until smooth. Stir in the parsley, agave, and salt.
Pour the sauce over the chicken or serve alongside as a dipping sauce.
In a food processor, combine the spinach, bread crumbs, cheese, lemon zest, salt and pepper. Blend until the spinach is finely chopped. Transfer the mixture to a medium bowl. In another medium bowl, mix together the buttermilk and chicken. Using a slotted spoon, transfer the chicken, allowing any extra buttermilk to drip back into the bowl, into the bread crumb mixture. Toss until the chicken pieces are coated.
In a 12-inch, high-sided skillet heat the oil over medium-high heat (the oil is hot enough when a pinch of breadcrumbs sizzles when added to the pan). Add 1/3 of the chicken and fry for 3 minutes on each side until golden and crispy. Drain on paper towels. Repeat with the remaining chicken.