Saute leeks, shallots, and bacon in a skillet over medium heat until fat is extracted from the bacon, about 5 minutes. Add white wine and bring to a simmer.
Add cream, peas, Parmesan cheese, carrots, butter, and dried tarragon; bring to a simmer. Add clams, cover, and steam until clams open, 7 to 10 minutes. Season with salt and pepper.