Available at good Italian delis, salted anchovies are a great alternative to fresh ones.
Remove the spines from the anchovies with your fingers, gently easing them out.
Rinse the anchovies in cold water. Place them in a single layer in a dish and add the juice of 1 lemon and vinegar. Marinate for 30 minutes.
Rinse them again and squeeze gently between sheets of paper towels or in a clean kitchen towel. Lay them on a serving dish and dress with the onion, garlic, chile, the remaining lemon juice, oil, and parsley. Leave them to marinate for 3 hours or up to overnight. If the oil sets in the refrigerator, wait for them to reach room temperature before eating. Serve with toasted bread.