Place English muffin halves on foil-lined baking sheet. Broil until lightly toasted; set aside.Cut each shrimp crosswise in half; set aside.
Heat oil in large nonstick skillet over medium-high heat until hot. Add bell pepper. Cook and stir 3 minutes. Add shrimp, green onions and garlic; cook and stir 2 minutes or until shrimp are opaque. Remove from heat; stir in lemon juice, salt and black pepper.
Evenly divide shrimp mixture among toasted English muffin halves; top each with 1 tablespoon cheese. Broil 2 minutes or until cheese melts. Sprinkle with parsley, if desired.
Timesaving Tip:* Raw peeled, deveined shrimp is sold frozen in supermarkets. Follow the quick-thaw package directions for ready-to-use shrimp in minutes.