Left indexing fire radical
火 (Kangxi #86) — pictograph of flames rising. Carries the meaning core: stir-frying is by definition a high-flame cooking method. Anchors
炒 in the cooking family alongside
烤 (roast),
烧 (cook),
煎 (pan-fry),
炖 (stew),
炸 (deep-fry). The Chinese culinary verbs are sorted by what the fire is doing, and
炒 is the quick-toss-over-flame member of that set.