Asparagus-and-Spinach Toast with Fontina Cheese

Snap off tough ends of asparagus. Melt butter in a large nonstick skillet over medium-high heat. Add onions; sauté 1 minute. Add asparagus, water, and salt; bring to a boil. Reduce heat, and simmer 5 minutes. Add spinach; simmer 3 minutes. Stir in basil and pepper. Sprinkle 1 tablespoon cheese over each toast slice; cut each slice diagonally in half. Place 4 toast halves on each of 2 plates. Spoon 1 cup asparagus mixture over each serving.