Cook the pasta until al dente. Reserve 1/4 cup of the pasta water, then drain the pasta and return it to the cooking pot.
Meanwhile, in a large skillet, heat the butter and olive oil over medium heat. Once melted, add the garlic and calabrian chili paste and cook until the garlic is fragrant about 60 seconds. Add the wine and pepper, increase the heat slightly, and cook until bubbling, about 2 minutes. Add the clams, increase the heat, cover, and cook just until the clams open, about 3 minutes.
If any clams don’t open, discard them and transfer the opened clams to the pasta pot. Taste the sauce and adjust salt and pepper as needed.
Warm through over medium heat, adding the reserved pasta water as needed to help make it extra saucy. Toss in the parsley, chives, lemon zest and lemon juice. Garnish with extra herbs and serve as needed.