Step 1

Whisk together sugar, ½ cup of the vinegar, and ¼ cup of the oil in a small bowl. Transfer to a large ziplock plastic bag; add steak. Seal bag; massage steak and marinade to coat completely. Chill at least 2 hours or up to 12 hours.

Step 2

Place peas in a large pot; add water to cover by 2 inches. Bring to a boil over high. Reduce heat to medium-low. Simmer, undisturbed, until peas are tender and just cooked through, 25 to 30 minutes. Drain; set aside until ready to use.

Step 3

Meanwhile, remove steak from refrigerator; let come to room temperature, about 30 minutes.

Step 4

While peas cook and steak rests, whisk together 1 tablespoon of the oil, ½ teaspoon of the salt, and remaining 1 tablespoon vinegar in a small bowl. Set aside vinaigrette.

Step 5

Heat 1 tablespoon of the oil in a large cast-iron skillet over medium-high. Add corn ears. Cook, turning corn often, until charred, about 5 minutes. Remove from skillet. Add 1 tablespoon of the oil to skillet, and add bell pepper planks. Cook over medium-high until starting to soften and charred on both sides, 2 to 3 minutes per side. Remove skillet from heat. Remove peppers from skillet; cool about 5 minutes.

Step 6

Cut corn kernels from cobs; discard cobs. Chop pepper planks into ½-inch pieces. Place corn, peppers, and peas in a large bowl. Add reserved vinaigrette; toss to combine. Set aside until ready to serve.

Step 7

Remove steak from marinade; discard marinade. Pat dry with paper towels; sprinkle evenly with black pepper and remaining 1 ½ teaspoons salt. Add remaining 1 tablespoon oil to skillet, and return to heat over high. Add steak; cook until charred on both sides and desired degree of doneness (2 to 3 minutes per side for medium-rare, 125°F). Remove from skillet; let rest 15 minutes.

Step 8

Slice steak against the grain into ½-inch-thick strips. Spoon field pea mixture onto a platter, and top with sliced steak. Sprinkle with chives and flaky sea salt.