In a medium skillet, heat the olive oil over medium-high heat. Add the asparagus and cook until tender, but still crisp, about 4-5 minutes. Make sure you stir the asparagus occasionally. Remove from heat and set aside.
Cut the avocado in half lengthwise. Remove the pit from the avocado and discard. Remove the avocado from the skin and place the avocado flesh into a small bowl. Add the lemon juice, chives, salt, and pepper. Mash with a fork until smooth and creamy.
Spread mashed avocado on toasted bread slices. Add the asparagus, peas, pistachios, and feta cheese. Season with salt and black pepper, to taste. Serve immediately.