Lay out the bacon rashers in a cold panini press, being careful to not overlap them. Cook on high until the bacon is crisp, 7 to 8 minutes. (If your machine doesn’t have heat settings, just plug it in and turn it on.)
Remove the bacon and set aside on a paper towel, then take a look at how much fat remains in the press. Ideally, you’ll have about 2 tablespoons, but depending on the fat content of your bacon, you may have more. What I do in this case is fold a couple of paper towels, place in the press, close the lid, count to three, then carefully remove and discard.
Add the red onion pieces, distributing them evenly. Close the press and cook for 4 minutes. Remove to a bowl, then add the mushrooms in a single layer. Close and cook until the mushrooms are brown, 2 to 3 minutes. Add to the bowl with the onions. Repeat with the spinach, cooking for no more than 30 seconds before moving to the bowl.
Crumble the bacon into the bowl, dress with the hot sauce, and serve.
After enjoying, you’re going to look at the panini press and curse me because now you have to clean it. This is made easier by turning the machine off, allowing it to cool, laying a few moistened and folded paper towels across the lower surface, and closing the lid for about 10 minutes. Then wipe clean and store…the machine, not the paper towels.
In professional kitchens, this is called “frenching” an onion.
Recipe courtesy of Alton Brown and Elizabeth Ingram