Coat a 10-in nonstick pan with cooking spray and heat on medium-low heat.
In a bowl, whisk together eggs, milk and season with salt and pepper.
Pour egg mixture into pan and cover with a lid. Do not scramble! Cook until set (about 3-4 minutes), flip and finish cooking (about 1-2 minutes).
Lay tortilla flat and spread with avocado leaving a 2-inch border around the edges.
When eggs are finished cooking, place in the center of the tortilla and top with spinach.
Start at one end and roll tightly, but gently.
Coat the same skillet with nonstick spray and warm on medium-high heat.
Place roll seam-side down on skillet and brown slightly on both sides. Remove and allow to rest for 1-2 minutes.
Mix Greek yogurt, Sriracha and teaspoon of milk in small bowl.
Using a serrated knife, slice 1-inch size pieces, drizzle with spicy sauce and serve with chopsticks.