Lime-Pickled Red Onions

1 large red onion, thinly sliced
1/4 cup fresh lime juice
1 Tbs. olive oil
1/2 tsp. salt
2 Tbs. chopped fresh cilantro
1 tsp. chopped fresh oregano or 1/2 tsp. dried oregano

Mix all ingredients together and let the onion marinate in the refrigerator. The onion will keep for days if covered in the refrigerator. Try these onion slices in tacos, quesadillas, and on sandwiches of all sorts. They can also be used to liven up grilled fish or chicken breasts.