Let Me Tell You About This Low Carb Philly Cheesesteak Casserole

I still remember the first time I tried to make anything Philly cheesesteak-ish without the bread—felt a bit like trying to dance with two left feet, honestly. But one blustery Tuesday last fall, I had a fridge full of odds and ends (plus one bell pepper on the edge of questionable), so I sort of threw everything into a casserole dish and hoped for the best. Guess what? My brother inhaled half of it before I even grabbed a fork. It’s now the only low carb thing he’ll actually request—miracles do happen, folks. And, no, it’s not the prettiest dish in the world. But it’s hearty, cheesy, unfussy, and fast enough that dinner doesn’t drag on ‘til midnight. Plus, anything with melty cheese is basically already halfway to being forgiven for any flaws.

Why You’ll Love This (Or Why my People Do Anyway!)

I make this whenever I need something filling but don’t want to faff about with a zillion ingredients. My family goes bonkers for it as long as there’s extra cheese (I learned the hard way: just add more cheese from the beginning). If you’re chasing that good, cozy comfort food feeling, this checks the box without leaving you dozing on the couch for hours after. Oh, and if the weather’s grim, it actually makes me look forward to dinnertime. Even my youngest, who normally avoids onions like the plague, eats this, so that says something. (Though, full admission—once I tried subbing turkey in here and let’s just say… won’t be repeating that!)

Here’s What You’ll Need

1 1/2 pounds thinly sliced steak (ribeye if you’re feeling fancy, but honestly any beef that’s not shoe-leather works. I sometimes just use leftover roast beef, too.)
2 green bell peppers, chopped (or whatever color is rolling around in your crisper drawer—I’ve used red and yellow, nobody complained)
1 large onion, sliced (white or yellow; my sister says red onion is “sacrilege” but I’ve done it in a pinch and survived)
8 ounces mushrooms, sliced (optional, but I’m convinced they’re essential for texture. No mushrooms? No biggie.)
3 cloves garlic, minced (I often cheat and use the stuff in a jar… shh.)
1 teaspoon salt, plus more to taste
1/2 teaspoon black pepper
6 slices provolone cheese (or a handful of shredded—I mean, who even measures cheese?)
4 ounces cream cheese, cubed (I’ve forgotten this and it still works. But it’s better creamy.)
1 tablespoon Worcestershire sauce (Soy sauce kinda works in a tough spot—my granny would probably be horrified though!)
Olive oil for cooking

Alright, Let’s Cook This Thing

Preheat your oven to 375°F (about 190°C if you’re outside the States… or just guess, I’m not fussy). Grease a casserole dish—anything roughly 9×13 will work, but honestly if it fits, it ships.
Get a big skillet heating up over medium-high heat. Dash in a good glug of olive oil, then tumble in your onions and bell peppers. Cook ‘em until they soften and the onions start looking a bit golden, maybe 5-7 minutes? Add mushrooms and garlic, give it another few minutes. If things stick, splash in a bit of water. (This is where I usually sneak a taste, just to check the seasonings. Totally necessary research.)
Add the steak. If raw, toss it in and give it a quick stir fry until just cooked (don’t fuss about perfection—a little pink is fine, as it’ll bake more). If your beef’s already cooked, just stir to warm through. Sprinkle with salt and pepper.
Now, the magic—turn off the heat, drop in the cream cheese, and smoosh it around until it’s mostly melted. Pour in Worcestershire, stir, and toss everything together until it’s sloppy and sort of homogenous (don’t panic if it looks a tad odd. It’ll smooth out while baking.)
Scoop it all into your prepared dish. Lay the provolone slices over the top, overlapping as needed (sometimes I do a zigzag pattern, but that’s just for my own amusement).
Bake uncovered for about 18-20 minutes, until the cheese is gooey and starting to bubble. If you like a browner top, you can kick on the broiler for 2-3 minutes—just watch it, cheese goes from golden to burnt quicker than you’d think (learned that one the hard way!)
Let it rest a couple minutes before digging in, though I often fail at this step and burn my tongue. Every. Single. Time.

Notes I’ve Picked Up the Hard Way

If you slice steak super thin (like, paper thin), it cooks best and is waaay easier to scoop later—half the time I just pop it in the freezer for 20 minutes first then slice away.
I find it actually tastes even better re-heated the next day, but maybe that’s just because I can eat it standing over the sink, undisturbed.
Oh, and if you forget mushrooms, don’t fret; add more peppers, it’s all good.
One time I forgot to drain some extra liquid off before baking, so the bottom got a bit soupy. Still perfectly edible, but next time, I just tip off any excess, problem solved.

Other Versions I’ve Tried (Some Work, Some… Eh)

Chicken swap: Chopped leftover rotisserie chicken works. It’s not classic, but honestly, who cares?
Spicy kick: I added a diced jalapeño once. Regretted it though (my dad’s lips tingled for an hour, he swears).
Cheese experiment: Monterey Jack instead of provolone actually worked. Swiss? Uh, not so much—the flavor fought the steak.
Veggie-packed: I tried sneaking in cauliflower, but it just… didn’t blend in. Maybe with rice, but this isn’t that kind of party.

What If You Don’t Have the Usual Tools?

No oven-safe skillet? No big. Just fry things up in a pan, then dump it all into whatever baking dish fits. And in a pinch, I’ve used a glass pie dish—it looked a little funny, but dinner’s dinner, right?

How to Store This (Though Honestly, Good Luck With Leftovers!)

If by some miracle you don’t eat it all the first round, just cover the dish (foil, plastic wrap, heck, I’ve used a big plate before) and stash it in the fridge. Lasts maybe 3 days? Probably even longer, but I wouldn’t bet the farm. It does microwave well—actually, I think the flavors mellow out even better overnight.

How I Like to Serve It

I’m a purist, so I just scoop it up with a big spoon and maybe a quick side salad (bagged Romaine in my usual reality). My cousin loves it over zucchini noodles, but to me that’s just extra steps. Sometimes—don’t tell anyone—I eat it cold for breakfast. Wild, I know.

Pro Tips (AKA Lessons from the School of Oopsies)

Don’t rush softening the veggies—if you leave them too crunchy, the casserole comes out all uneven. I once tried microwaving to save time, and it turned out, well, weirdly soggy and crunchy at the same time. Not my best moment.
If your cheese burns, that’s usually the universe saying you forgot to check the oven, so take it from me: stay nearby during the last few minutes.
And, if you overload on veggies trying to make this almost “healthy”—it can get watery. Less is more (for once).

Real Questions I Get from Friends

Will it taste just like a real Philly cheesesteak?
Eh, not exactly—it’s missing the roll (obviously), but the flavor’s pretty darn close. My brother says it’s better (he’s obviously biased).
Can I freeze it?
You can, but honestly it’s a bit mushier when thawed. If you must, wrap well and reheat in the oven, not the microwave.
What steak is best?
Ribeye if you want to splash out. Otherwise, honestly, whatever looks good or is on sale. I use whatever the butcher has that’s in thin strips.
My kids hate mushrooms—skip or swap?
Totally skip! Or try little diced zucchini. On second thought, maybe just skip.
I’m dairy free—what do I do?
Hmm, I haven’t done it, but a friend used shredded vegan cheese and said it was “pretty good, all things considered.” Your mileage may vary!

If you reach the end and still have questions, message me—I like talking food and I’ve probably tried (or ruined) every variation under the sun. Anyway, hope you love this as much as my motley crew does, and don’t be shy about making it your own. Happy cooking!

Low Carb Philly Cheesesteak Casserole