Pesto Gnocchi Bake

• 1 tbsp extra virgin olive oil
• 1 onion, finely diced
• 3 garlic cloves, crushed
• 190 g jar basil pesto
• 75 g frozen spinach
• 300 g broccoli, grated
• 1 cup green peas, frozen
• 500 g potato gnocchi
• 1 cup milk
• .5 cup vegetable stock
• .5 cup light sour cream
• 100 g bocconcini