Rinse the clams thoroughly.

Discard any with cracked shells or those that do not close tightly when tapped.

Finely chop the clam meat after shelling.

Heat the olive oil in a skillet over low heat.

Add the chopped onion and cook, stirring occasionally, until the onion turns translucent and softens, around 5 minutes.

Cover and cook for an additional 20 minutes until the onion is tender but not browned.

Uncover the skillet, increase the heat to medium-low, and add the garlic, parsley, and crushed red pepper flakes.

Cook for 2-3 minutes, then stir in the flour.

Increase the heat to medium-high.

Add the reserved clam juice (or water) and the chopped clams to the skillet.

Cook until the mixture thickens enough to be spreadable.

This can be prepared in advance.

Cut each slice of bread diagonally to create triangles.

Spread the clam mixture generously on each toast triangle.