Charred Green Beans with Hazelnuts and Serrano Chile

If you’re using different varieties of beans, divide them among different bowls and divide the oil and salt among the bowls. (You can use just one large bowl if you’re using only one varietal.) Toss the beans with the oil and salt until evenly coated. Heat a griddle or two large skillets over high heat. (Work in batches if using one varietal, and work by type if using multiple varietals.)

When the surface is smoking hot, spread the beans in an even layer on the griddle or in the skillets and add another drizzle of oil (about a teaspoon per skillet or a tablespoon for the whole batch). When the bottoms brown and blister, toss the beans and continue cooking, tossing occasionally, until there’s a nice char on the beans but they still have a little bite, 3 to 5 minutes. Thinner beans will brown more quickly, so pull them from the heat first. As the batches of beans cook, transfer them to a plate to continue cooking the remaining beans. Once the last batch is done, remove them from the heat, return all the beans to the skillet and let them soften in the residual heat, about 7 minutes.

While the beans rest, soak the scallions in a medium bowl of ice water until crisp, about 5 minutes, then lift out and gently pat dry with paper towels.

Put the hazelnuts on a cutting board and crush with a heavy skillet or the flat side of a knife until they crack into smaller pieces. On the board, drizzle the nuts with ½ teaspoon olive oil, sprinkle with ⅛ teaspoon salt and toss until evenly coated. Transfer two-thirds to a bowl and add the beans, scallions and lemon juice to the bowl and toss well. Add the chile and dressing and toss again. Taste and add more dressing if you’d like. Transfer to serving plates, top with the chives and remaining hazelnuts, and serve immediately.

Pulse both mustards with the vinegar, garlic and lemon juice in a mini food processor until smooth. With the machine running, drizzle in the olive oil. Or, you can make the dressing by hand: Whisk both mustards with the vinegar, garlic and lemon juice in a medium bowl. While whisking, slowly drizzle in the olive oil. Continue whisking until the dressing is emulsified.