Pantry Clean-Out Cream of Mushroom Soup Casserole

There’s a certain magic that happens when the refrigerator light flickers on at 6:15 p.m. and you realize you haven’t grocery-shopped in ten days. The produce drawer holds a single limp celery stalk, the dairy shelf shelters a half-cup of milk that’s probably still good, and the pantry looks like a crime scene of half-empty pasta boxes and random canned goods. It was on one of these “what on earth are we going to eat?” nights that this Pantry Clean-Out Cream of Mushroom Soup Casserole was born. I yanked the lonely can of cream of mushroom soup from the back corner, combined it with a handful of barley, the last of the frozen mixed vegetables, and a forgotten bag of french-fried onions left over from Thanksgiving. Forty-five minutes later my husband took one bite, looked at me with wide eyes, and said, “Please tell me you wrote this down.” Since then, this casserole has become our family’s go-to comfort supper when the budget is tight, the clock is louder than our stomachs, and the snow is piling up outside. It feels retro in the best possible way—like the casseroles my grandma brought to every church potluck—yet it’s forgiving enough to absorb whatever odds and ends your kitchen is begging you to use up. One skillet, one baking dish, and dinner is done. Let’s turn those pantry stragglers into the meal your future self will thank you for.

Ingredients You'll Need

Before we talk swaps, let’s celebrate the originals. A humble can of condensed cream of mushroom soup is the silky backbone of this casserole. Choose the “reduced sodium” version if possible; you’ll control the salt later. You’ll whisk it with low-sodium broth (chicken or vegetable) to loosen the texture into a luxurious sauce. Quick-cooking barley adds pleasant chew and soaks up flavor without turning mushy—look for “10-minute” on the label. If you only have traditional pearl barley, no worries; we’ll adjust liquid and bake time.

Frozen mixed vegetables save prep time and provide color, but feel free to sub an equal amount of leftover roasted vegetables, canned corn, or even that half-bag of peas that’s clumping together. Aromatics matter: onion and garlic powders live in the spice drawer forever, yet they bloom beautifully in hot fat. If you have a fresh onion or garlic cloves, sauté them for five minutes in butter before adding to the mix. Protein is optional but delightful: canned tuna, diced ham, rotisserie chicken, or a drained can of chickpeas all work.

Finally, the crown: french-fried onions deliver retro crunch, but buttered panko or crushed Ritz crackers keep things just as cozy. For a dairy-free spin, swap the traditional milk with unsweetened oat or almond milk and use vegan fried onions (yes, they exist).

How to Make Pantry Clean-Out Cream of Mushroom Soup Casserole

Expert Tips

Variations to Try

• Broccoli-Cheddar: Swap mixed veg for frozen broccoli and stir 1 cup shredded sharp cheddar into the sauce before baking.
• Southwestern: Use cream of celery soup, add black beans + corn + diced green chiles, season with cumin & chili powder, top with crushed tortilla chips.
• Seafood: Fold in a can of baby shrimp + diced pimientos, replace thyme with Old Bay seasoning.
• Wild Rice & Almond: Sub pre-cooked wild rice, add sliced mushrooms, top with slivered almonds for crunch.
• Breakfast-for-Dinner: Use cream of potato soup, fold in diced ham & frozen hash browns, top with shredded Monterey Jack.

Storage Tips

Cool leftovers within 2 hours. Transfer to airtight containers; refrigerate up to 4 days or freeze individual portions up to 3 months. The barley continues soaking up moisture, so revive with a splash of broth when reheating—stovetop on medium-low works best, though the microwave is fine for single bowls. If the onion topping loses its crunch (inevitable after refrigeration), sprinkle fresh fried onions or toasted breadcrumbs just before serving.

For potlucks, assemble the casserole but do not add the crunchy topping. Transport covered in a cooler, then bake on site so the topping stays crispy. If you must reheat an already-baked casserole, cover with foil and warm at 300 °F for 20 minutes, uncovering for the last 5 to re-crisp.

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Pantry Clean-Out Cream of Mushroom Soup Casserole

(4.9 from 127 reviews)

Prep

10 min

Cook

35 min

Servings

6

Ingredients

• 1 can (10.5 oz) condensed cream of mushroom soup
• 1 cup low-sodium chicken or vegetable broth
• ½ cup milk (dairy or unsweetened plant milk)
• 1 tsp soy sauce
• ½ tsp Worcestershire sauce
• ½ tsp dried thyme
• ½ tsp onion powder
• ¼ tsp garlic powder
• ½ tsp kosher salt + ¼ tsp black pepper
• 1 cup quick-cooking barley (or rice)
• 1 ½ cups frozen mixed vegetables
• 1 cup cooked protein (tuna, chicken, ham, chickpeas) — optional
• 1 cup french-fried onions (or buttered panko)
• Chopped parsley for garnish

Instructions

1. Preheat: Preheat oven to 375 °F. Grease a 2-quart baking dish.
2. Whisk: In a large bowl whisk soup, broth, milk, soy sauce, Worcestershire, thyme, onion powder, garlic powder, salt, and pepper until smooth.
3. Fold: Stir in barley, frozen vegetables, and optional protein. Pour into dish; cover tightly with foil.
4. Bake covered: Bake 25 min (quick barley) or 40 min (pearl barley) until grains are nearly tender.
5. Top: Remove foil, scatter french-fried onions on top. Bake 8–10 min more until bubbly and golden.
6. Rest & serve: Let stand 5 min, garnish with parsley, and scoop into bowls.

Recipe Notes

For pearl barley increase broth to 1¾ cups and bake covered 40 min. Store leftovers refrigerated up to 4 days or freeze up to 3 months.

Nutrition (per serving)

318

Calories

18g

Protein

38g

Carbs

11g

Fat