Wash the asparagus and chop it into 1-½ inch pieces. In a dry skillet over medium-high heat, cook the asparagus, stirring occasionally. After 3 minutes, add ¼ cup water and cook for another 3 to 4 minutes. Taste a piece, and continue to cook until the thickest pieces are tender. Optional: prepare a bowl of ice cold water, and place the cooked asparagus in the ice water for 1 minute (this keeps the asparagus bright green, helpful when preparing in advance).
Chop the chives. Mix the chives with the Greek yogurt and a scant ½ teaspoon kosher salt. Add small amounts of water (up to 4 tablespoons) until a creamy consistency is reached.
Drain the ricotta cheese of any excess liquid. In a medium bowl, crack the eggs and whisk them together until well-beaten. Add 1/2 teaspoon kosher salt and plenty of fresh ground black pepper.
In a skillet, heat the butter over medium heat. Tilt the pan to ensure the entire pan is coated in the melted butter, the pour in the eggs. Keep the heat on medium low. When the eggs just start to set, use a flat spatula to slowly scrape sections of eggs, creating folds. Scrape occasionally until the eggs form soft folds; turn off the heat just before they are fully hardened. Add dabs of ricotta cheese and a few pinches of kosher salt. Mix in the cheese roughly while the heat is off, then remove the eggs to a bowl to avoid overcooking.
To serve, place the scrambled eggs on a tortilla and top with asparagus spears and yogurt chive sauce.