Core and deseed the red pepper and roughly chop the flesh. Peel the cucumber and roughly chop the flesh. Roughly chop the spring onion, reserving a few shreds for a garnish.
Pour the tomato juice into a food processor or blender, add the pepper, cucumber and spring onion and process briefly. Taste, then season to taste with lemon juice, hot pepper sauce, Worcestershire sauce and salt and pepper.
Pour the smoothie into a glass, garnish with the remaining spring onion and serve immediately.