To make these breakfast sandwiches, start by preparing the green onion pesto. Add all of the pesto ingredients to a food processor and pulse until smooth. Transfer the pesto to a separate container and set aside.
Next, preheat your oven to 425 F.
Take two standard-size baking sheets and line them with parchment paper. You may want to lightly spray the trays with oil in order for the parchment paper to stick to them.
Next, cut open the English muffins and line them across the two baking sheets.
Then, take the pesto and spread it evenly across the bottoms of the English muffins, followed by the ham and the cheese. One side of the English muffins will be plain!
Roast the English muffins, in the oven, for 10-12 minutes, until the cheese is melted and the edges of the English muffins have browned.
Once they're done, remove them from the oven and spread more pesto across the plain halves of the English muffins.
Finally, assemble the sandwiches, serve, and enjoy! To store any leftovers, wrap them individually in foil and place them in the fridge or freezer until you're ready to eat them. When you're ready to eat them, simply remove them from the foil, pop them into the microwave, and enjoy!