How to Make It
Preheat oven to 425°F. Drizzle potatoes with oil, and rub to coat. Sprinkle with pepper and 3/4 teaspoon of the salt. Spread in a single layer on a baking sheet, and bake until skins are slightly crispy and potatoes are tender when pierced, about 25 minutes.
Meanwhile, melt butter in a medium skillet over medium. Add bell peppers, Broccolini, and shallots, and cook, stirring occasionally, until tender-crisp, about 3 minutes. Stir in remaining 1/4 teaspoon salt. Slit each potato lengthwise. Gently push the ends toward the center to split them open, like miniature baked potatoes. Spoon about 2 teaspoons bell pepper mixture into each potato. Serve warm.