Combine chicken with yogurt and tikka paste. Marinate for 1–2 hours, or overnight, in the refrigerator.
Cook the onion in oil until soft. Add the marinated chicken and cook, stirring, until the chicken reaches 165°F in the thickest pieces.
Stir in the tomatoes, salt, and pepper. Bring to a simmer and cook for 10 minutes.
Mix in the cream and butter. Cool promptly in shallow containers, refrigerate until cold, then freeze flat in a food-safe freezer bag.
At camp, thaw in a refrigerator or ice-packed cooler kept at 40°F or below, or reheat directly from frozen in a saucepan with a splash of water. Heat throughout to 165°F, stirring often to prevent sticking.