Combine couscous, green onion, jalapeño, olive oil, cumin, cayenne pepper, and black pepper in a large bowl; stir until olive oil is completely incorporated.
Bring vegetable stock, asparagus, and peas to a boil in a saucepan over high heat.
Pour stock, asparagus, and peas over couscous mixture; shake the bowl to settle couscous into liquid. Cover and let stand for 10 minutes. Fluff with a fork, then stir in mint and season with salt and pepper to taste.
