Low-Fat Green Bean Casserole: 4 g of Fat a Serving, Topping Still Crunchy

Low-Fat Green Bean Casserole: 4 g of Fat a Serving, Topping Still Crunchy

The version most of us grew up with is built on two tins: condensed cream of mushroom soup and fried onions. Between them they put 14–16 g of fat on every plate, and almost none of it tastes of mushroom or onion. It tastes of the oil they were cooked in.

Strip both tins out and the dish usually collapses into pale beans in thin milk. That is because fat was doing two separate jobs here, and they need two separate replacements — body for the sauce, and crunch for the top.

This version comes out at 4 g of fat and 145 calories a serving, serves eight, and the onions on top still shatter when you put a spoon through them.

Why this version works

The body comes from the mushrooms themselves. Cooked dry in a hot pan with no oil, they squeak, then flood the pan with their own liquor, then brown as it cooks away. That liquor is concentrated mushroom stock, and it is what the tinned soup was imitating with cream. Thicken it with cornflour slurried into evaporated skimmed milk — which carries twice the protein of ordinary milk per 100 ml and sets to a proper coating consistency — and you have a veloute with no roux and no cream in it.

The crunch is a separate problem. Fried onions are crisp because deep frying drives the water out fast. A hot oven does the same thing more slowly, and a dusting of flour and panko gives the surface something to crisp into. One teaspoon of oil across a whole onion is enough; more and the shreds steam instead of drying. The topping goes on in the last five minutes so it never sits in the sauce.

Ingredients

Serves 8. For the casserole:

• 700 g green beans, trimmed and halved
• 400 g chestnut mushrooms, sliced
• 1 tsp olive oil
• 1 medium onion, finely diced
• 3 garlic cloves, minced
• 2 tbsp cornflour (cornstarch)
• 300 ml evaporated skimmed milk
• 200 ml low-sodium chicken or vegetable stock
• 1 tsp soy sauce
• ½ tsp dried thyme
• ¼ tsp ground nutmeg
• salt and black pepper

For the topping:

• 1 large onion, sliced as thinly as you can manage
• 1 tbsp plain flour
• 30 g panko breadcrumbs
• 1 tsp olive oil
• ¼ tsp salt

Instructions

1. Heat the oven to 220 °C (425 °F). Toss the thinly sliced onion with the flour, panko, oil and salt until every shred is dusted, then spread it in one loose layer on a lined baking sheet.
2. Bake the topping for 12–15 minutes, stirring twice, until it is the colour of mahogany and rattles when you shake the tray. Set it aside and drop the oven to 200 °C (400 °F).
3. Boil the green beans for 4 minutes, drain, and drop them straight into cold water. Drain again and pat them properly dry — wet beans thin the sauce.
4. Put the mushrooms in a wide pan over high heat with no fat at all. They will squeak, then release their liquid, then sizzle again as it cooks away. Keep going for 8–10 minutes until they are browned and the pan is almost dry.
5. Add the teaspoon of oil, the diced onion and the garlic. Cook for 4 minutes with a splash of the stock to stop anything catching.
6. Whisk the cornflour into the evaporated milk until there are no lumps, then pour it in with the remaining stock, the soy sauce, thyme and nutmeg. Simmer for 3–4 minutes, stirring, until it coats the back of a spoon.
7. Fold in the beans, taste and season, and tip the lot into a 2-litre baking dish.
8. Bake for 20 minutes, until it is bubbling at the edges. Scatter the crisp onions over the top and give it 5 minutes more.
9. Let it sit for 5 minutes before serving. The sauce tightens as it rests.

Nutrition

Per serving (one eighth of the dish):

• Total fat: 4 g
• Saturated fat: 1.2 g
• Calories: 145
• Protein: 7 g
• Carbohydrate: 21 g
• Fibre: 4 g
• Sodium: 390 mg (with low-sodium stock)

The 4 g is the two teaspoons of oil and the small amount that comes with the mushrooms and milk. Leave the oil out of the sauce entirely — sweat the onion in stock instead — and a serving lands just under 3 g.

Variations

• No mushrooms. Use 400 g of finely chopped leek cooked down the same way, and add a teaspoon of mustard powder to the sauce for depth.
• Make it a main. Fold in 300 g of shredded cooked chicken breast with the beans. It adds about 1 g of fat and 12 g of protein a serving.
• Frozen beans. They work; skip the boiling step and add them straight from frozen, then bake 5 minutes longer.
• Gluten free. Swap the flour and panko for cornflour and crushed gluten-free cornflakes.

Storing and making ahead

The sauced beans keep in the fridge for three days and reheat well, covered, at 180 °C for 20 minutes. Store the crisp onions separately in an airtight tin at room temperature — they stay crunchy for two days and go soft the moment they meet the fridge.

You can assemble the whole dish, minus topping, the day before. Take it out of the fridge half an hour before it goes in the oven and add ten minutes to the bake.

What to serve it with

It is a side, and it is at its best next to something plain: roast turkey breast, a simple baked chicken, or a tray of roast root vegetables. If you are building a low-fat holiday table around it, put it next to a stuffing that is not swimming in butter and you have the two heaviest dishes of the meal handled.

Green beans almost never travel alone on a holiday table, and the dish sitting next to them is usually the bigger problem: classic stuffing soaks up half a stick of butter before it ever reaches the oven. The same approach works there too — low-fat stuffing that stays moist inside and crisps on top gets both textures from stock and a hot pan instead of fat.

Questions People Ask

Can I just use a reduced-fat tin of soup instead?

You can, and it will be quicker. Reduced-fat condensed mushroom soup runs around 2 g of fat per 100 g, so a tin adds roughly 1 g of fat a serving here — the saving is real but small, and the sodium goes up sharply. The fresh sauce takes about eight extra minutes and tastes of mushrooms rather than of thickener.

Why did my onion topping go soft?

Three usual causes: the slices were too thick, they were crowded on the tray so they steamed, or they went on too early. Slice as thin as you can, spread them loosely across a full sheet, and add them only in the last five minutes of baking.

Can I make this for a crowd?

It doubles cleanly in a large roasting tin. Cook the mushrooms in two batches rather than one crowded pan — piled up they stew instead of browning, and you lose the flavour the whole sauce rests on.

Is 4 g of fat a serving low enough for a low-fat diet?

For most people working to a per-meal fat limit, a 4 g side leaves plenty of room for the rest of the plate. If you are following a specific limit set by a clinician, check it against your own numbers — and take the oil out of the sauce, which brings the serving under 3 g. This is a recipe, not medical advice.

Written by

Sophia W. Whitman

Recipe developer and author of the Pancreatitis Diet Cookbook for Beginners. Cooking has been my life’s work, and low-fat cooking is the corner of it I know best. Every recipe here lists fat per serving, so you don’t have to guess.

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