Label gallon freezer bag with name, date, and reminder to add broth after thawing. Add raw chicken, drained lentils, sweet potato, onion, garlic, ginger, tomatoes, cumin, and salt. Press out excess air; seal.
Immediately freeze flat on tray; store up to 3 months for best quality. Keep broth, peanut butter, and lime juice separate from raw bag.
Thaw bag completely in rimmed dish in refrigerator 24 to 48 hours at 40°F or below. Empty entire bag into 6-quart slow cooker; add measured broth. Do not start with frozen chicken.
Cover; cook on low 6 to 7 hours until chicken reaches 165°F, lentils soften, and sweet potato breaks easily under spoon.
Lift chicken to board; shred into short pieces. Whisk peanut butter with ladleful of hot broth in bowl until smooth; return with chicken to cooker.
Cook on high 15 minutes until evenly hot; add lime juice. Divide into six servings.
For cooked freezer portions, promptly cool in shallow containers; refrigerate within 2 hours. Chill fully before covering; freeze up to 3 months.
Reheat one cooked frozen portion with measured reheating water in a small covered saucepan over low. Stir and break apart as it softens; simmer until all reaches 165°F, usually 20 to 30 minutes.