Step 1 Rinse the blossoms and pat dry. Remove the pistils if you like. Slice crosswise into thin strips (if blossoms are particularly large, slice lengthwise first). Set aside strips from 2 blossoms for garnish.
Step 2 Bring a large pot of water to a rolling boil.
Step 3Meanwhile, heat the olive oil in a large, deep skillet over medium heat. Add the garlic and pepper flakes and cook until softened but not browned. Stir in the blossoms and season well with salt. Flake the tuna into the pan. Cook, stirring, until the blossoms are softened, about 2 to 3 minutes. Add the stock and continue cooking 5 minutes. Keep warm while cooking the pasta.
Step 4Add salt to the boiling water, then add the linguine and cook until al dente, according to package directions. Drain well, then immediately transfer to the skillet. Toss until all ingredients are mixed. Serve at once.