Cook the rice noodles according to the package instructions. Rinse with cold water and set aside.
Heat your grill on high for at least 10 minutes, then turn the heat to medium.
To make the sauce, in a medium bowl, whisk together the peanut butter, soy sauce, lime, maple, and garlic until smooth. Transfer about ⅔ cup of the sauce into a separate bowl (we’ll use this later).
Add the chicken to the bowl with the remaining sauce and toss to coat. If grilling, drizzle with a bit of olive oil to prevent sticking.
Grease your grill grates if they’re prone to sticking. Place the chicken on the grill and cook, covered, for 3-4 minutes or until you have nice grill marks and it easily releases from the grill (reduce the heat if it’s burning). Flip and repeat until cooked through, about 2-3 more minutes. Transfer to a cutting board. Slice or chop it up.
To the reserved sauce, whisk in the water until combined. You want the consistency to be very loose so it easily coats everything without getting dry/gloppy. You can keep adding a bit more water until you reach a good consistency. I ended up using an extra tablespoon of water.
Pour the sauce in your bowls (I enjoy putting the sauce on the bottom, but you could also pour it on top). Top with the rice noodles, veggies, cucumber (if using), chicken, herbs, and peanuts. Top with a squeeze of lime, mix it all up and enjoy!