Heat grill to high; lightly oil grates. Season steaks with salt and pepper; grill 4 to 5 minutes per side for medium-rare. Transfer to a plate; let rest 10 minutes.
Meanwhile, grill onion until tender and charred, 4 to 5 minutes per side. Transfer to a plate; separate into rings. (To store, refrigerate steaks and onion, up to 1 day.)
Assemble sandwiches: Thinly slice steaks against the grain. Dividing evenly, spread top halves of bread with cheese, and bottom halves with mustard. Pile steak, onion, and arugula on bottom halves; close sandwiches. Cut each sandwich into quarters, and serve.
I hear you, Mary! I don't have an outdoor grill either. But Dznyma makes a great point -- cast-iron grill pans make a great substitute for small-scale grilling, like making these steak sandwiches.
There are indoor grills available and they do a great job. True, you may not get the exact same flavor, but it is a great alternative.
There are indoor grills available and they do a great job. True, you may not get the exact same flavor, but it is a great alternative.
Why is it always assumed that everyone has a BBQ? Many who live in apartments and condos are not permitted to BBQ. It seems that every Father's Day recipe starts with "Fire up the grill!"