When the mushrooms hit the butter, they release a surprising amount of liquid before they begin to brown. I let that moisture cook away before adding anything else; it gives the sauce a deeper savory flavor and keeps the casserole from tasting watery. That little pause is part of what makes this No Cream Soup Cheesy Green Bean Casserole taste like it came together in a skillet, not from a can.
Instead of condensed soup, the sauce starts with butter and flour, then gets whisked with broth and whole milk until it thickens. Sharp cheddar melts in off the heat, so the sauce stays smooth and the cheese flavor comes through without taking over.
Once the green beans are coated, everything bakes in a 9×13-inch dish until the edges bubble. The crispy fried onions go on near the end, so they finish golden on top of a creamy, cheesy casserole.
Kitchen Note
Take the skillet off the heat before adding the cheddar. The residual warmth melts it into the sauce without continuing to cook the cheese over the burner.
Save this no-cream-soup green bean casserole for a bubbling cheddar sauce and a golden fried-onion topping.
Why a Casserole Can Turn Watery Even With a Thick Sauce
A sauce that looks thick in the skillet can still end up loose in the baking dish if the green beans carry extra water into it. Canned beans are convenient, but the liquid clinging to them after rinsing is enough to thin the sauce once everything is mixed together. The flour thickens the broth and milk; it can’t make excess rinse water disappear.
Let the beans drain thoroughly in a colander before stirring them into the skillet. Don’t rush straight from rinsing to mixing. The sauce should already coat the back of a spoon before it meets the beans, which gives the casserole a head start on holding together as it bakes. If the beans are still dripping, give them more time in the colander rather than trying to compensate with extra flour in the skillet. That keeps the sauce balanced and lets the cheddar stay smooth instead of turning the casserole pasty.
The Ingredients That Give This Sauce Its Body and Bite
- Canned cut green beans — Their tender texture suits the short bake, and the cut pieces mix evenly with the sauce. Choose plain canned beans rather than a seasoned style so the mushrooms, cheddar, and sauce stay in balance.
- Cremini mushrooms — These add savory depth and give the sauce more character than a plain milk-based mixture. Buy firm mushrooms with dry-looking caps; slicing them evenly helps them cook at the same pace.
- Butter and all-purpose flour — Together, they form the base that thickens the broth and milk. Stir the flour into the cooked mushrooms and butter so it’s distributed before you start whisking in liquid.
- Low-sodium chicken broth and whole milk — Broth brings savory flavor, while whole milk gives the sauce a creamy body. Low-sodium broth leaves more room to season with the kosher salt in the skillet.
- Sharp cheddar — Its tang cuts through the creamy sauce and pairs well with the earthy mushrooms. A block you shred yourself usually melts more smoothly than pre-shredded cheese, which can contain anti-caking ingredients.
- Canned crispy fried onions — They bring the familiar crunchy top without needing a separate topping mixture. Keep them in their can until you’re ready to scatter them over the casserole.
Building the Mushroom-Cheddar Sauce Before It Goes in the Oven
Get the Beans and Baking Dish Ready
Drain and rinse the green beans, then leave them in a colander to drain thoroughly. Heat the oven to 350°F while you prepare the sauce. Lightly grease a 9×13-inch baking dish with the canola oil so the casserole releases more easily when you serve it. Having the dish ready before the sauce is finished keeps the assembly moving.
Brown the Mushrooms and Thicken the Sauce
Melt the butter in a 12-inch skillet over medium heat, then add the sliced mushrooms, kosher salt, and black pepper. Cook for 6 to 8 minutes, stirring occasionally, until the mushrooms are browned and their liquid has evaporated. Stir in the minced garlic for 30 seconds, then add the flour and cook for 1 minute. Gradually whisk in the broth and milk, bring the mixture to a simmer, and cook for 3 to 5 minutes, whisking often. You’re looking for a sauce that coats the back of a spoon; remove the skillet from the heat and stir in the cheddar until it melts.
Bake First, Then Add the Crunch
Stir the drained beans into the sauce and transfer the mixture to the prepared baking dish, spreading it evenly. Bake uncovered for 25 to 30 minutes, until the casserole bubbles around the edges. Scatter the crispy fried onions evenly over the top only after that first bake. Return the dish to the oven for 5 to 8 minutes, watching for the onions to turn golden. Let the casserole rest for 5 minutes before serving so the sauce can settle.
Two Swaps That Change the Casserole Without Losing Its Shape
Make It Vegetarian
Replace the low-sodium chicken broth with the same amount of low-sodium vegetable broth, and choose a sharp cheddar made with vegetarian-friendly rennet. The sauce keeps its creamy structure, with a slightly less savory base than the chicken-broth version.
Turn Up the Cheddar
Use extra-sharp cheddar in place of sharp cheddar, keeping the same amount. It gives the sauce a more pronounced tang against the mild green beans and crunchy onions; shred it finely so it melts evenly into the warm sauce.
Storage and Reheating
- Refrigerator: Refrigerate leftovers within 2 hours and keep them covered for 3 to 4 days. The fried onions will soften as they sit.
- Freezer: Freeze cooled portions in an airtight container for up to 2 months for best quality. The sauce may separate a little when thawed, and the onion topping won’t stay crisp.
- Reheating: Warm portions in a 350°F oven, covered loosely with foil, until hot throughout; check that leftovers reach 165°F. Avoid reheating uncovered for too long, since the onions can darken before the center warms.
Questions That Come Up Before the Casserole Goes in the Oven
No Cream Soup Cheesy Green Bean Casserole
Ingredients
Equipment
Method
- Drain and rinse the green beans, then let them drain thoroughly in a colander.
- Heat the oven to 350°F.
- Lightly grease a 9x13-inch baking dish with the canola oil.
- Melt the butter in a 12-inch skillet over medium heat.
- Add the mushrooms, salt, and pepper and cook for 6 to 8 minutes, stirring occasionally, until the mushrooms are browned and their liquid has evaporated.
- Stir in the garlic and cook for 30 seconds.
- Stir in the flour and cook for 1 minute.
- Gradually whisk in the broth and milk, bring to a simmer, and cook for 3 to 5 minutes, whisking often, until the sauce is thick enough to coat the back of a spoon.
- Remove the skillet from the heat and stir in the cheddar until melted.
- Stir the drained green beans into the sauce.
- Transfer the mixture to the prepared baking dish and spread it evenly.
- Bake uncovered for 25 to 30 minutes, until the casserole is bubbling around the edges.
- Scatter the crispy fried onions evenly over the top.
- Bake for 5 to 8 minutes, until the onions are golden.
- Let the casserole rest for 5 minutes before serving.
