Bring a large pot of well-salted water to a boil. Cook the pasta 1 minute less than package directions. Reserve ½ cup of pasta water, then drain.
While the pasta cooks, heat the olive oil and butter in a large skillet over medium heat. Add the shallots and asparagus and sauté until the shallots are translucent, about 3 minutes. Add the cherry tomatoes and cook 1 minute more, just until they start to soften. Add the garlic and cook 30 seconds, until fragrant.
Pour in the white wine and let it reduce by half, about 1 minute. Add the drained pasta, heavy cream, ¼ cup of pasta water, and grated parmesan, tossing to coat. Bring to a gentle simmer and season pasta with salt and pepper. If the pasta sauce is too thick, add more pasta water as needed.
Remove the skillet from the heat. Add the smoked salmon and lemon juice, tossing gently. Adjust seasoning with salt and pepper. Finish with a sprinkle of lemon zest and chopped chives and serve immediately.
Notes
Use a dry, crisp white wine such as Pinot Grigio or Sauvignon Blanc. Avoid anything sweet or heavily oaked.