- Heat the oil in a large skillet over medium-high heat. Add onion and cook, stirring, until starting to brown, 30 seconds to 1 minute.
- Add beans and cook, stirring often, until seared in spots, 2 to 3 minutes. Add water; cover, reduce heat to medium and cook, stirring occasionally, about 3 minutes for tender-crisp or 6 minutes for tender.
- Remove from heat and stir in bacon, hazelnuts and salt.