Step 1: Fill a large pot with water and bring to a rolling boil. Generously salt water. Trim greens and scrub beet. Add to boiling water and cook until tender, about 28 minutes. Using tongs, remove beet and allow to cool completely. Using a paring knife, remove skin from cooled beet.

Step 2: Preheat oven to 400°F. Wrap beet in non-stick foil and roast in oven until tender, about 40-50 minutes. Allow the beet to cool completely. Using a paring knife, remove skin from roasted beet.

Step 3: Purée beet in a food processor using a metal blade. Add eggs and yolk and process until well combined. Add flour and 1/2 teaspoon of salt and process until dough comes together, about 15-20 seconds.

• Transfer dough to well-floured surface. Knead dough until it is smooth and flexible but not sticky, adding small amounts of flour as needed, 5 to 7 minutes. Gather dough into a ball and flatten into a disk. Cover in plastic wrap and allow dough to rest for at least 10 minutes and up to 1 hour at room temperature.
  

Step 4: Using a bench scraper, cut dough into 2 pieces. Keep extra dough covered in plastic wrap while working with one piece. With a rolling pin flatten dough into a rough rectangle. Using a pasta machine or Kitchen Aide past machine attachment set to the widest setting, roll dough through machine. Take dough and fold it in thirds. Turn dough so one open end faces machine and roll it through on widest setting again. Fold, turn and roll once more on the widest setting.

• Continue rolling pasta through machine adjusting to a smaller setting on each pass. Once you kit the second to last setting on your pasta machine, stop. If pasta sheet gets too large to handle, cut it into manageable lengths and continue rolling.

Step 5: To shape the tagliatelle: Generously flour one sheet of pasta and loosely roll it into a cylinder. Using a sharp knife, cut roll into 1/3" ribbons. Unwrap ribbons, toss them with flour and create piles on a baking sheet dusted with semolina. The pasta can be cooked immediately or covered with plastic wrap and refrigerated for up to 24 hours before use.

Step 6: To cook the pasta: To a large pot of water set over high heat, add water to 2/3 full and bring to a boil. Generously season water with salt. You want your water to be like sea water, nice and salted. Add pasta and stir immediately to prevent pasta from sticking together. Boil until al dente, 2 to 3 minutes. Reserve 1 cup of pasta water and drain pasta. Use reserved pasta water to thin your chosen pasta sauce.

To freeze the pasta: Transfer shaped tagliatelle on baking sheet to freezer. Once frozen, transfer frozen pasta to a storage bag. The pasta can be kept frozen up to 2 months. The pasta does not need to be thawed before cooking. Frozen pasta will take an extra 1-2 minutes to fully cook.