In a small bowl, whisk together the Greek yogurt, minced garlic, lemon zest, half of the lemon juice, and half of the chopped fresh herbs until smooth.
Trim the woody ends of the asparagus and heat olive oil in a skillet over medium heat, sautéing the spears for 4 to 5 minutes until they are crisp-tender and bright green.
Bring a medium pot of water to a very gentle simmer and carefully crack the eggs into the water, poaching for about 3 minutes until the whites are set but the yolks remain runny.
Toast the sourdough bread until it is golden brown and crisp.
Spread the lemon-herb yogurt mixture onto a plate or directly onto the toast, then layer the smoked salmon and sautéed asparagus on top.
Carefully place the poached eggs over the asparagus, drizzle with the remaining lemon juice, and garnish with the remaining fresh herbs, sea salt, and black pepper.