In medium saucepan, melt 2 tablespoons butter and cook onion until tender. Add water and bring to a boil. Stir in noodles & sauce, butter & herb and continue boiling over medium heat, stirring occasionally, 8 minutes or until noodles are tender.
Meanwhile in 30 cm skillet, heat remaining 2 tablespoons butter with olive oil and cook garlic over medium high heat 30 seconds. Add shrimp and artichokes and cook, stirring occasionally, 3 minutes or until shrimp are opaque. Stir in parsley and pepper.
To serve, combine shrimp mixture with hot noodles. Garnish, if desired, with watercress.