Step 1: Prepare the Caramelized Shallots

1. Thinly slice the shallots into rings. Use a mandoline or sharp knife for precision.
2. Heat 1/4 cup olive oil in a skillet over medium-high heat until shimmering.
3. Add the shallots and stir until sizzling. Lower the heat and cook for 25–30 minutes, stirring occasionally, until the shallots are golden brown and caramelized.
4. Remove with a slotted spoon and transfer to a paper towel-lined plate. Sprinkle with flaky sea salt.

Step 2: Roast the Green Beans

1. Preheat the oven to 450°F (convection roast if possible).
2. Spread the trimmed green beans on a rimmed sheet pan. Toss with 2 tablespoons olive oil and 1.5–2 teaspoons kosher salt.
3. Roast for 15 minutes, stir, then roast for another 5–10 minutes until the green beans are crisp-tender with lightly charred edges.

Step 3: Assemble and Serve

1. Remove the green beans from the oven and toss with 2–3 teaspoons white balsamic vinegar. Taste and adjust seasoning with additional salt or vinegar if needed.
2. Transfer the green beans to a serving platter and top with the caramelized shallots.
3. Serve immediately or at room temperature.