Heat a large, heavy-bottomed soup pot over high heat, add the oil (2 turns of the pan), and when you see the oil ripple, add the onion, carrots, mushrooms and poblano peppers. Season the vegetables with salt and pepper and cook, stirring frequently, for 2 minutes. Add the garlic, snow peas, stock and 2 cups of water. Cover with a lid and bring to a boil. When the soup is boiling, add the noodles and reduce the heat to a simmer, then cook for 5 minutes more at a low rolling bubble. Remove the soup from the heat, add the cilantro, basil, pea shoots and lime juice, and serve.