In a large bowl, toss together the green beans, mushrooms, lemon juice, garlic powder, sage, onion powder, salt, and pepper. Spray the mixture with oil from an oil sprayer, then toss again to coat. Transfer the mixture to your air fryer basket.
Air fry at 400° F for 10-15 minutes, shaking once or twice during cooking.
Serve topped with french fried onions, if you're using them.
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Notes
If french fried onions aren't your thing, you can top these with nuts or seeds instead. Cashews, pumpkin seeds, or sliced almonds would all give you that little bit of crunch that the onions deliver. You can also omit the onions, if you want a lighter dish. Nutritional information includes the onions.Sage and green beans are a lovely combo, but feel free to mix up your spices! You can simply omit the sage or replace it with other dried herbs, like Italian seasoning, chili powder, or more garlic powder.The range in cooking times is because green beans can vary so much in size! Skinny beans will cook up more quickly, maybe even before the 10-minute mark. Fatter beans might need the whole 15 minutes to get cooked to preference.