Avocado Breakfast Tacos

In a blender or food processor, pulse the tomatoes and chipotle peppers until mostly smooth, about 1 minute.
Add the sesame seeds, if using, and season with salt. Pulse to combine, about 30 seconds. Taste and add more salt if needed. (You can stash the salsa in an airtight container in the fridge for up to 2 weeks.)

In a medium bowl, whisk together the eggs and a pinch each of salt and pepper.
In a large skillet over medium heat, fry the bacon until the fat renders and the bacon is crisp, 5 to 6 minutes. Use a slotted spoon to place the bacon on a paper towel-lined plate.
In the same skillet over medium heat, cook the shallots, stirring occasionally, until golden brown, about 4 minutes.
Remove the shallots from the skillet and drain on the paper towel-lined plate. The shallots will crisp as they cool.
Wipe out the skillet, return it to medium heat, and melt the butter. Add the beaten eggs and cook, undisturbed, until a thin white layer forms around the edge of the skillet. Using a rubber spatula, gently push the eggs around the skillet until fluffy and barely set, 2 to 4 minutes.
Immediately scrape the eggs onto a plate and gently fold in the cheese.
Place each tortilla on a plate and top with the spinach or kale, if using, eggs, and avocado. Sprinkle with the bacon, shallots, and, if desired, scallions and/or cilantro. Serve with lime wedges and salsa on the side.