Bring a pot of water to a boil and drop in the frozen peas, cooking for 3 minutes. Before draining, save ⅓ cup of the cooking water, then rinse the peas under cold water to halt cooking.
In a blender, combine the drained peas, reserved water, fresh herbs, lemon juice, and sea salt. Blend until smooth, then optionally pass the mixture through a fine sieve for extra creaminess. Set aside the pea purée.
Warm the stock in a saucepan and keep it at a gentle simmer.
In a large frying pan or shallow pot, melt the butter with olive oil over medium heat. Add the diced onion and cook for about 3 minutes until softened, making sure not to brown.
Add the garlic to the pan and cook for another 2 minutes, stirring regularly.
Stir in the arborio rice and cook for a few minutes until the grains are translucent and well coated.
Pour in the white wine and stir until it is mostly absorbed, maintaining a gentle simmer without boiling.
Begin adding the simmering stock one ladle at a time, allowing each addition to absorb completely before adding the next, stirring often.
After 15 minutes from the first ladle of stock, stir in the chopped asparagus and continue cooking, adding stock as needed, for another 10 minutes or until the rice is tender but still slightly firm to the bite.
Remove from heat, then mix in the grated parmesan cheese.
Fold in the pea purée, season with salt and several cracks of black pepper, and add a knob of butter if desired for extra richness.
Serve the risotto garnished with lemon zest, extra parmesan, and a drizzle of high-quality extra virgin olive oil.
