Put a pot of water on the stove and bring to a boil in heavily salted water. Cook spaghetti according to the package instructions.
Melt butter in a pan on medium heat. Add the garlic and toss until you can smell it. About 2 minutes. Add the frozen peas, and 1/2 cup of water to the pan. Let the peas cook until the water has evaporated, about 5 minutes.
Add the lemon zest, parsley and Romano cheese and use a spatula or other flat kitchen implement to squish the peas roughly. Taste it and add a bit of salt and freshly ground pepper according to your taste. They don't have to be smooth, but you do want the peas to be squished enough to form a sort of loose pesto that will coat your pasta nicely.
Once the spaghetti is cooked add it to the pan with the pesto and toss. Add water a few tablespoons at a time to help loosen the sauce so everything is coated.
Serve hot with extra parsley and grated Romano. Squeeze a little lemon juice on it if you feel like it.
Serve as is or for a little crunch add some crushed almonds or toasted breadcrumbs.