Melt 1 tablespoon of butter in a large sauté pan over medium heat. Add the diced carrots, onion, peas, and minced garlic, seasoning generously with salt and pepper. Cook for about 5 minutes, or until the onion and carrots are softened.
Increase the heat to high, add the remaining butter, and stir until it’s fully melted. Next, add the cooked rice, green onions, soy sauce, rice vinegar, and wasabi paste, stirring everything together until well combined. Sauté for another 3 minutes, stirring occasionally, to let the rice fry and crisp up a bit.
Once the rice is nicely fried, stir in the fresh herbs. Taste and adjust the seasoning with more soy sauce if needed.
Serve immediately, or store in a sealed container in the refrigerator for up to 3 days.