1. Prepare your bagels: Begin by slicing each sourdough bagel in half horizontally. You can toast them lightly in a toaster, under the broiler, or in a dry skillet for a few minutes until they are golden brown and slightly crispy. This adds a wonderful texture and prevents the bagel from getting soggy.

2. Cook the bacon (if not pre-cooked): If your bacon isn’t already cooked, fry it in a skillet over medium heat until it reaches your desired crispiness. Lay the cooked bacon on a paper towel-lined plate to drain any excess grease.

3. Scramble the eggs: In a medium bowl, whisk the eggs with milk or cream, a pinch of salt, and a dash of black pepper until well combined. Melt butter or heat olive oil in a non-stick skillet over medium heat. Pour in the egg mixture and scramble gently until cooked through but still soft and fluffy.

4. Assemble the cheese: Immediately after scrambling, divide the hot eggs into four portions. Place a slice of cheese over each portion of hot egg in the skillet (or on a plate if you’ve removed the eggs) to allow it to melt slightly from the residual heat.

5. Prepare the spread: In a small bowl, mix together the mayonnaise and Dijon mustard. Spread a generous amount of this mixture onto the cut sides of both halves of each toasted bagel.

6. Layer the sandwich: On the bottom half of each bagel, layer a handful of fresh spinach or arugula. Top with the cheesy scrambled eggs, followed by two slices of cooked bacon.

7. Add avocado and finish: Arrange a few slices of ripe avocado over the bacon. Place the top half of the bagel onto the assembled sandwich, gently pressing down to secure the fillings.

8. Serve immediately: Enjoy your freshly made sourdough bagel sandwiches while they are warm and the cheese is still melty.