Start by trimming the broccolini and cooking it briefly in salted boiling water until tender and bright green. Transfer it to ice water to stop cooking and preserve color. Meanwhile, pulse fresh bread in a food processor and toast the crumbs in olive oil until golden and crisp.
Bring a large pot of salted water to a boil and cook the linguine until al dente. While the pasta cooks, melt butter in a skillet and sauté the white parts of the green onions with garlic until fragrant. Add black pepper to deepen the flavor base.
Stir lemon juice and a splash of pasta water into the skillet to create a light sauce. Add the cooked linguine and broccolini, tossing to coat evenly. Mix in Parmesan so it melts smoothly, then finish with olives, chives, lemon zest, and crispy breadcrumbs before serving.