In a large pot of boiling salted water, cook 12 ounces penne rigate or other short pasta according to package instructions. Meanwhile, in a small saucepan, melt 1 1/2 tsp unsalted butter. Add 3 tbsp shallot minced; season with salt and pepper. Cook until soft, about 5 minutes. Add 1/4 cup dry white wine and cook until evaporated, about 5 minutes. Add 1 c heavy cream; bring to a boil. Reserve 1/2 cup pasta water; drain pasta and return to pot. Add cream mixture to pasta pot, along with 1 tsp fresh lemon juice, 4 oz smoked salmon, and 2 tbsp chopped fresh chives. If necessary, adjust consistency with reserved pasta water and season with salt and pepper.