Peel and thinly slice approximately 2 cups of shallots. In a skillet over medium-high heat, add 2 tablespoons of olive oil and toss in the shallots, then reduce the heat to low. Stir occasionally for about 15-20 minutes until the shallots transform into a deep amber color.

While the shallots caramelize, trim the ends of 2 pounds of fresh green beans and rinse them under cold water. Toss the green beans with 2 tablespoons of olive oil and salt to taste. Spread them on a baking sheet lined with parchment paper in a single layer.

Preheat your oven to 450ºF (232ºC). Once hot, place the baking sheet with the green beans inside. Roast them for 15-25 minutes, tossing halfway through for even cooking until crisp-tender and slightly blistered.

Remove the roasted green beans from the oven and transfer to a large serving bowl. Drizzle 1 tablespoon of vinegar over them and toss gently to coat. Adjust seasoning with more salt if needed.

Spoon the caramelized shallots on top of the green beans and serve immediately.