Make The Tahini Dressing: Combine tahini, 3 tablespoons of lemon juice, cilantro, honey, water, a pinch of salt, and a few cranks of pepper in a food processor or blender and process until smooth. Taste and add more lemon, honey, water, or salt, as desired (you want it to be the consistency of melted ice cream)
Bake The Toasts: Meanwhile, heat the oven to 350°F and arrange a rack in the middle. Brush the bread with olive oil, season with salt, and bake until golden brown, about 5 to 10 minutes.
Shave The Asparagus: Holding the end of the asparagus stalk, use a vegetable peeler to shave the asparagus into long thin strips (don't worry if the tips snap off). Combine the shaved asparagus and any tips in a bowl, add a drizzle of olive oil and some salt and pepper and toss to coat.
Assemble The Toast: When you're ready to make the toasts, halve and pit the avocados, and mash with a fork. Put about 1/4 of an avocado on each toast, then top with a spoonful of dressing and a handful of asparagus (folding them on themselves, so they fit on the toast). Top with a bit of salt and serve.