Preheat oven to 350°F (180°C). Place artichokes in a baking dish, cutting bottom of artichokes to sit level, as necessary.
Spoon 3/4 tsp (4 mL) pesto into centre of each artichoke. Combine goat cheese, 1/4 cup (60 mL) roasted red peppers, olives and capers. Top artichokes with goat cheese mixture. Bake artichokes until cheese is melted, 20 to 25 min.
Meanwhile, combine tomatoes, lemon juice, olive oil and remaining roasted red peppers. Spoon red pepper sauce onto eight plates, top each with a stuffed artichoke; sprinkle with green onion.