Cook pasta according to package directions, omitting salt and fat. Reserve 3 tablespoons pasta water; drain pasta. Combine reserved pasta water, 1 teaspoon olive oil, and lemon juice in a small bowl; set aside.
While pasta cooks, place a large skillet over medium-high heat until hot. Add almonds and cook, stirring constantly, 1 to 2 minutes or until toasted. Set almonds aside.
Coat skillet with cooking spray; add remaining 1 teaspoon oil. Return to medium-high heat until oil is hot. Cut onion slices in half; add onion and garlic to skillet. Cook, stirring constantly, 4 minutes or until tender. Add spinach, and cook, stirring constantly, 2 minutes; stir in almonds, salt, and pepper. Stir in reserved pasta water mixture. Add pasta, and toss gently. Serve immediately.
This recipe doesn't have a thick sauce. So, adding some of the pasta water back to the pasta mixture helps the pasta stay moist.
Cooking Light Low-Fat, Low-Calorie Quick and Easy Cookbook