Bake vol-au-vent shells according to package directions.
In the jar of a blender, add avocado, lemon juice and 2 tbsp. water. Process until smooth and thin (not too thin) by adding a little bit more water to it until desired consistency.
Add avocado to béchamel sauce and whisk until incorporated; taste and adjust if necessary.
Place a piece of wax paper on top making sure it covers the surface, move the sauce to the back burner and keep it warm until ready to serve.
In a medium bowl, add eggs and season with salt and pepper; beat well and set aside.
In a skillet over medium heat, add hot Italian sausage and break the meat into small pieces. Cook until no longer pink, about 5 to 7 minutes.
When it’s done, use a slotted spoon and transfer the meat to a bowl; set aside.
In the same skillet, add onions and sauté for 2 minutes. Add red, orange and poblano peppers; sauté for 3 minutes.
Return hot Italian sausage back to the skillet and mix everything together.
Add the beaten eggs and stir until they’re almost cooked. Add cheese and continue cooking, stirring constantly, until the eggs are cooked and the cheese is melted.
To assemble… Generously and evenly fill up the cavities of 6 vol-au-vent pastry shells with the egg mixture. Spoon avocado sauce on top and garnish with chopped cilantro. Serve immediately.