Bring a large pot of water to a boil.
Heat olive oil over medium high heat in large skillet, add bacon and crisp. Remove to a plate; add onions to the drippings and reduce heat a bit. Cook to soften then add garlic, corn and thyme; cook until corn just begins to lightly brown. Add stock, bring to a bubble and reduce a minute or so. Stir in mascarpone cheese and reduce heat to low.
Salt boiling water and cook pasta to al dente. Add a ladle of starchy cooking water to the sauce, drain pasta and add to pan. Toss with corn sauce, bacon and a handful of cheese. Toss vigorously to combine and serve in shallow bowls with parsley and chives on top; pass extra cheese at table.