unsalted butter • baby leeks, roots, trimmed and thinly sliced (about 1 1/4 cups) • garlic cloves, minced • kosher salt • finely chopped fresh tarragon, plus more for serving • finely chopped fresh thyme, plus more for serving • shredded Gruyère cheese • large eggs • plus 2 tablespoons (90ml) heavy whipping cream • flaky sea salt, for serving • Freshly ground black pepper, for serving • Toast points, for serving