In a medium-sized skillet, heat the oil and sauté the garlic for 3 to 5 minutes.
Add the spinach and sauté for 3 to 5 minutes more. Set aside.
Preheat oven to 400°F.
Sprinkle the loin with the salt and black pepper.
Spread the split tenderloin with the reserved spinach mixture, bell pepper strips, cheese, and pine nuts. Roll up the stuffed tenderloin and roll in the flour, then in the egg wash. Coat with the bread crumbs.
Place the loin in a preheated, large, oiled baking pan and brown on all sides.
Roast for 15 to 20 minutes, or until a meat thermometer reads 160°F.
Remove from oven and let stand for 10 to 15 minutes.
Slice and serve with the prepared Arugula Pesto.