Keep in mind this is a recipe that works with any soft, leafy green. See the headnotes for details. Once made and oiled, you can keep spaetzle in the fridge for a few days.
Bring a large pot of water to a boil and salt it well; it should tasty quite salty. Get a bowl of ice water ready. Plunge the greens into the water and boil for 1 minute (up to 4 minutes for chard). Move to the ice water to shock.
Chop the greens roughly, leaving them wet. Put into a blender and puree. If you need to add some ice water to get the blades to turn correctly, do that. You want the puree to be as thin as heavy cream.
Add the remaining spätzle ingredients (except the oil) to a bowl. Pour out 1 cup of puree. If you have extra you can use it in some other recipe, but it should be pretty close. Mix well. You want the batter to be slightly thicker than pancake batter. The key to remember is that you want to be able to pour it into a spätzle maker without it flowing through the holes too fast.
Get that pot of water boiling again and make the spätzle. A spätzle maker has a little hook on it to anchor it to the edge of a pot. Rock the hopper of the maker back and forth to make the dumplings. You'll likely need to do this in several batches. When the dumplings float, give them another minute and then move to baking sheet. Toss with a little vegetable oil. When the spätzle are all done. make sure they are slightly oiled so they don't all stick together. In this way, they can be stored in the fridge a few days.
When you are ready to eat, fry the bacon in a large pan. Remove, eat one piece, and chop the rest. Leave as much fat in the pan as you want, at least 2 tablespoons. Add the spätzle to the pan and sear hard for a minute. Shake the pan and keep searing until about 1/3 of the spätzle has some nice browning. Move to a bowl.
Add the broth and bring to a boil, scraping off any browned bits with a wooden spoon. Add the saffron if you're using it. Add back the spätzle, and the peas and bacon. Toss to combine and serve.