- Marinate onions with the lime juice at room temperature for at least 30 minutes.
- Drain the onions in a fine sieve set over a bowl, removing as much liquid as possible.
- Reserve the marinade.
- In a heavy 8" to 10" skillet, melt the butter over moderate heat.
- When the foam begins to subside, add the onions and, stirring frequently, cook for 5 minutes, until they are soft and transparent but not brown.
- Stir in the chopped chilies and garlic, reduce the heat to low, cover the skillet tightly, and cook for about 10 minutes, or until the chilies are tender.
- Off the heat stir in the reserved marinade and the salt.
- Cool to room temperature before serving.
- Covered tightly and refrigerated, sauce ti-malice can be kept safely for about 5 to 7 days.