Warm the cream and garlic in a saucepan over low heat. Simmer for 10 minutes or until the cream has thickened.
Remove the cream from heat and reserve a little for the egg yolk. Add 3/4 of the uni to the sauce. Using an immersion blender, blend until smooth and strain through a sieve; keep warm.
Start a pot of salted boiling water for the spaghetti and cook until al dente. Strain the pasta and add it to a hot pan, then add the uni sauce and cook for a couple more seconds. Beat the egg yolks with the reserved cream. Remove the hot pan from the stove and slowly pour in the egg mixture while stirring to prevent it from turning into scrambled eggs.
Add a handful of grated Parmesan cheese and stir. Season the pasta to taste with salt and pepper. Plate the pasta and garnish with shrimp or caviar, and top with herbs such as chives or parsley.
Notes
You may top the uni pasta with a few shrimp. Season the shrimp with salt and pepper. In a hot pan, pan-sear until the shrimp are cooked. Add the shrimp as a topping.