Equipment
Ingredients
Salad Base
- 500 g green beans, trimmed
- 50 g red onion, thinly sliced
- 15 g kosher salt
Balsamic Vinaigrette
- 45 ml extra virgin olive oil
- 30 ml balsamic vinegar
- 5 g dijon mustard
- 1 garlic, minced or grated
- 2 g kosher salt
- 1 g black pepper, freshly cracked
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 152 kcal
- Protein
- 3 g
- Carbohydrates
- 12 g
- Fat
- 12 g
- Fiber
- 4 g
- Sugar
- 6 g
- Sodium
- 1673 mg
- Saturated Fat
- 2 g
- Monounsaturated Fat
- 8 g
- Polyunsaturated Fat
- 1 g
- Potassium
- 299 mg
- Calcium
- 56 mg
- Iron
- 1.5 mg
- Magnesium
- 35 mg
- Phosphorus
- 55 mg
- Zinc
- 0.3 mg
- Vitamin A
- 44 mcg
- Vitamin C
- 16 mg
- Vitamin E
- 2.1 mg
- Vitamin K
- 61 mcg
- Vitamin B6
- 0.2 mg
- Thiamin
- 0.11 mg
- Riboflavin
- 0.13 mg
- Niacin
- 0.9 mg
- Folate
- 44 mcg
- Water
- 131 g
Sources: USDA FoodData Central
Method
Fill a large pot with water, add the heavy amount of kosher salt, and bring to a rolling boil at 100°C/212°F. Meanwhile, prepare an ice bath in a large mixing bowl filled with cold water and ice cubes.
Drop the trimmed green beans into the boiling water and blanch until vibrant green and crisp-tender. This should take about 3 to 4 minutes depending on the thickness of the beans.
Using a colander, immediately drain the green beans and plunge them directly into the prepared ice bath to halt the cooking process. Leave them submerged for 2 minutes, then drain thoroughly and pat dry.
In a medium bowl, combine the balsamic vinegar, Dijon mustard, minced garlic, kosher salt, and black pepper. Whisk constantly while slowly drizzling in the extra virgin olive oil until the mixture is fully emulsified and slightly thickened.
Place the dried green beans and thinly sliced red onions in a serving bowl. Pour the vinaigrette over the top and toss thoroughly to coat. Let the salad rest for 15 minutes before serving to allow the flavors to meld.
Chef's Notes
- Salting the blanching water is critical. It should taste like the sea. This seasons the beans from the inside out and helps set their vibrant green color.
- If raw red onion is too sharp for your palate, soak the slices in cold water for 10 minutes before tossing them into the salad to mellow their bite.
- The acid in the balsamic vinegar will naturally start to dull the green color of the beans over time. For the best visual presentation, toss the salad right before the 15-minute resting period.
- Using a high-quality, aged balsamic vinegar will significantly elevate the dish, adding a natural sweetness that balances the sharp mustard and pungent garlic.
Storage
Refrigerator: 3 days — Store in an airtight container. The beans will lose their bright green color due to the acid in the dressing, but they will develop a deeper, marinated flavor.
Troubleshooting
Green beans are mushy and have a dull olive-green color.
Cause: The beans were boiled for too long or not shocked quickly enough in the ice bath.
Fix: Cannot be fixed structurally, but they can still be eaten or repurposed in a slow-cooked dish.
Prevention: Test a bean at the 3-minute mark and transfer immediately to heavily iced water the second they are done.
Vinaigrette separates and looks oily.
Cause: The olive oil was added too quickly or the Dijon mustard was omitted.
Fix: Add a tiny drop of water or another pinch of mustard to the separated dressing and re-whisk vigorously before tossing the salad.
Prevention: Add oil in a slow, steady stream while whisking vigorously. Ensure mustard is used as it stabilizes the emulsion.
Dressing tastes watery on the beans.
Cause: The blanched beans were not dried sufficiently after the ice bath.
Fix: Drain the excess liquid from the salad bowl, re-toss with a fresh splash of olive oil and a pinch of salt.
Prevention: Pat the beans completely dry with a clean kitchen towel or paper towels before tossing.
Cultural Context
Fagiolini all'Agro, or green beans with an acidic dressing, is a cornerstone of simple Italian contorni (side dishes). Relying heavily on the quality of seasonal produce, this rustic dish highlights how a few pantry staples—premium olive oil and vinegar—can transform a humble vegetable into a bright, palate-cleansing accompaniment.
