Cut cauliflower into florets. Place in a large pot and cover with water or stock. Bring to a boil over high heat, then reduce heat to medium-low, cover, and simmer until fork-tender, 5 to 7 minutes.
Remove from water and place on a large baking sheet. Let cool slightly while pasta is cooking.
Place Jalapeno Fettuccine in the boiling water. Cook 3-4 minutes until desired doneness. Drain pasta, reserving some of the pasta water.
Place cauliflower, roasted garlic cloves, Parmesan, half of a cup of the cooking water or broth and cheese in a blender. Blend until smooth. Add more liquid if your sauce is too thick.
Taste the sauce and add salt and pepper to taste.
Use the sauce right away! Pour over cooked Jalapeno Fettuccine and top with additional Parmesan. If you are not using right away, pour sauce into a jar, cover, and refrigerate until ready to use.