Mix chicken, oats, egg, salt and pepper gently and refrigerate for 15 minutes. Shape into 24 equal meatballs with damp hands; chilling is included in prep time.
Heat 1 tablespoon oil in a deep 12-inch skillet over medium heat. Brown meatballs in 2 batches for 3 minutes per side, adding the remaining oil for the second batch, then transfer to a plate while partly cooked.
Add snap peas and their measured water to the skillet. Cover and steam for 2 to 3 minutes until bright green and crisp-tender, then transfer peas to a separate bowl.
Lower the heat and stir garlic into the skillet for 30 seconds. Add honey, soy sauce, lemon juice, red pepper flakes and broth and bring to a gentle simmer.
Return meatballs and their plate juices, cover partly and simmer for 6 to 8 minutes, turning once, until the largest centers reach 165°F.
Mix cornstarch and cold slurry water and stir into the simmering sauce for 1 minute until glossy. Fold snap peas back in, warm for 1 minute and serve 6 meatballs with one-quarter of the peas and sauce per portion.