- Combine yogurt and hot sauce to taste in a small bowl.
- Mash avocado in a bowl until chunky, and season with salt and pepper.
- In a large, straight-sided skillet, heat 2 inches of water until a few bubbles have broken the surface.
- Working with one egg at a time, crack into small bowl and gently pour into water, leaving space between each egg. Cook eggs until whites are just set and yolk is runny, 3-4 minutes.
- Carefully remove eggs from skillet and blot with paper towels to remove excess water.
- To serve, place a dab of mashed avocado on each plate to keep the tostada in place. Spread each tostada with mashed avocado, drizzle with yogurt sauce, top with poached egg, then cilantro, and finally tomatoes. Season with salt and pepper.