What’s Frenchie Dressing? The best mustard vinaigrette you’ve ever had

I’m completely obsessed with the green beans at Hippo. I know it has beans and nuts and serrano chiles, but I suspect that the “Frenchie dressing” is what puts these beans over the top. My attempts at reverse engineering this dish have been futile. Please help! I could just eat these for dinner any night and be happy.

–Amy Seidenwurm, Silver Lake

The green beans from chef Matt Molina, a Nancy Silverton protege who worked at Osteria Mozza, Pizzeria Mozza and Campanile, pack so many layers of textures and flavors. The green beans get seared hard in a skillet, giving them a deep smoky taste in minutes. The whole batch is good enough to eat just like that, but they’re even better with other goodies that add spicy heat, onion-y freshness and nutty crunch. The Frenchie dressing ties all those elements together and makes any salad better, so we’re giving you a bigger batch of that recipe to keep in the fridge for instant restaurant-worthy weeknight meals.

Charred Green Beans With Hazelnuts and Serrano Chile

20 minutes. Serves 4.

At Hippo, Matt Molina uses a mix of string beans he gets from local farmers. You can do the same or just stick with haricots verts, which are thin French green beans. You can buy hazelnuts that come roasted and skinned, or do it yourself: Toast the nuts in a 350-degree oven for 12 minutes, then wrap them in a clean kitchen towel and rub vigorously to remove skins. To crisp up raw scallions and soften their bite, Molina puts them in a small salad spinner and covers with ice-cold water. After a few minutes, he lifts them out, shakes off excess water and spins them dry.

1 pound string beans, preferably a mix of wax beans, haricots verts and dragon tongue beans, stem ends trimmed

1 tablespoon extra-virgin olive oil, plus more

1 1/2 teaspoons kosher salt, plus more

3 scallions, cut in 3-inch lengths and thinly sliced lengthwise

1/3 cup roasted, skinned hazelnuts

Kosher salt

1 tablespoon fresh lemon juice

1 serrano chile, very thinly sliced

2 tablespoons Frenchie dressing, plus more

1 teaspoon minced chives

1 If you’re using different varieties of beans, put them in separate bowls and divide the oil and salt among the bowls. (Use one large bowl for one varietal.) Toss 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, or by type if using multiple varietals.)

2 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 they have a nice char but they still have a little bite, three to five minutes. Thinner beans will brown more quickly, so pull them from the heat first. As the 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 seven minutes.

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

4 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. Drizzle nuts with half a teaspoon olive oil, sprinkle with one-eighth teaspoon salt and toss until evenly coated. Transfer two-thirds to a bowl; add the beans, scallions and lemon juice 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.

Frenchie Dressing

Makes about 1/2 cup

Two types of mustard and the combination of vinegar with lemon juice give this vinaigrette its complex, full-flavored tang. At Hippo, Molina and his team blitz this mix in a food processor so that the mustard seeds break up, highlighting their piquant taste. You can whisk the dressing instead and enjoy the pop of the whole mustard seeds. This dressing was created to go with charred green beans but is delicious on any salad, from leafy greens to roasted beets, and on grain bowls too.

1 tablespoon whole-grain Dijon mustard

2 teaspoons Dijon mustard

2 tablespoons white wine vinegar

1 small garlic clove, grated on a Microplane

1 teaspoon fresh lemon juice

1/3 cup extra-virgin olive oil

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.

Make ahead: The dressing can be refrigerated in an airtight container for up to one week.