Choose your base: tomato-forward (best) or a chili-forward salsa; start with the ratio that matches your closest pick.
Match heat and tang: taste your substitute and add chili powder/taco seasoning or a pinch of salt to get the same punch.
Match thickness for pouring: if it’s too thin, simmer 3–5 minutes; if too thick, thin with a splash of water/stock.
Let it rest 2–3 minutes so chili spices bloom, then pour over tortillas and fill as usual.
If baking (or slow-cooking), keep the sauce slightly looser than you want—it thickens as it heats.