Cook Brussels sprouts in boiling water 3 minutes or until crisp-tender; drain.
Heat a large nonstick skillet over medium heat; add prosciutto. Cook 6 minutes or until crisp, stirring occasionally. Remove from pan; set aside.
Heat pan coated with cooking spray over medium-high heat. Add Brussels sprouts; sauté 3 minutes or until lightly browned. Add butter, salt, and pepper, stirring until butter melts. Remove from heat; drizzle with juice. Add prosciutto; toss to combine.
Note: Pull off any limp outer leaves, and closely trim the stem end-don't cut too much off, or the Brussels sprouts may fall apart.