Place a medium deep saucepan on the stove over medium- heat and add olive oil. Once the oil begins to shimmer add shallot, and fennel bulb cook until translucent, about 4 minutes. Add the garlic, and crushed red pepper and cook until fragrant, about 1 minute.

Increase the heat to medium-high and add the littleneck clams, white wine and clam juice. Cover the skillet with a lid and allow the liquid to steam clams until open, about 4 to 5 minutes.

Remove the skillet lid, add the butter, fennel fronds and toss until well combined, about 1 minute. Taste and season with salt and pepper and serve immediately.

To serve: Divide among 4 warmed serving bowls, ensuring an even number of clams per bowl. Sprinkle with parsley and serve immediately.