TOSS the beans and scallions with a healthy glug of olive oil, ½ teaspoon salt, and many twists of black pepper.
SPREAD onto two baking sheets in a single layer, so the ingredients aren’t too crowded.
ROAST until nicely softened and browned—even charred—in places, 20 to 30 minutes. (Rotate the pans during cooking if you need to so everything cooks evenly.)
PILE the beans and scallions into a large bowl and sprinkle with the vinegar.
TOSS to mix and let rest for about 10 minutes to cool slightly.
WHISK together the pine nut vinaigrette, lemon juice, and
chile flakes in a small bowl.
POUR over the beans and scallions and toss to coat evenly.
TASTE the beans and dress with more lemon juice, salt, black pepper, or chile flakes to make the dressing zingy.
ADD the mint, basil, and pine nuts and toss gently again.
PINE NUT VINAIGRETTE
POUR the vinegar, fish sauce, and water into a small bowl or cup
PUT the pine nuts, garlic, chile flakes, and about half the vinegar mixture into a food processor and process until you have a slightly smooth puree, scraping down the sides of the bowl as needed. With the motor running, drizzle in the olive oil and then the rest of the vinegar mixture. The ingredients should emulsify into a creamy, thick-but-pourable dressing.
TASTE (watch out for the blade!) and adjust the flavors with more vinegar, fish sauce, or chile flakes. Adjust the consistency with more water if need be.
STORE in the fridge for up to 1 week.
TOASTED NUTS AND SEEDS
HEAT the oven to 350°F.
SPREAD the nuts or seeds on a pan in a single layer. For a small quantity, a pie plate is good; for more, use a rimmed baking sheet.
BAKE until you smell the nuttiness and the color is deepening slightly, 6 to 8 minutes for most whole nuts. Pine nuts will toast quickly, as will chopped or slivered nuts, and because of their small size, seeds cook the most quickly, so check early and often.
WHEN the nuts or seeds are done, transfer them to a plate so they don’t keep cooking on the hot baking pan. Determining doneness can be tricky, because the final texture won’t develop until they’re cool, so at this stage, you’re mostly concerned with color and flavor. To be safe, take them from the oven, let cool, taste one, and if not done enough, pop them back into the oven.