Meanwhile, in a very large skillet, cook bacon over medium heat until crisp. Transfer bacon to paper towels. Drain all but 1 Tbs. of the bacon drippings in the skillet. Add the onion and cook until tender, 6 to 8 minutes. Stir in the chickpeas and heat through. Add the spinach and cook, stirring constantly, until it wilts. Season with crushed red pepper and salt.