Cook fusilli as per package direction. Drain and set aside.
In a saucepan or skillet, heat oil in medium high. Cook shrimp for a minute each side or until they turn pink. Remove from pan and set aside.
In the same pan, saute garlic and onion until aromatic and tender. Add the crab fat and cook for a minute.
Stir in the cream and let it simmer for 3 minutes. Add the lemon or kalamansi juice and stir. Season with salt and pepper and add back the cooked shrimp. Simmer for another 2 minutes. (See Note 1)
Remove the shrimps again and transfer to a small bowl.
Transfer fusilli to a large bowl or casserole. Add the aligue sauce and toss until the fusilli are completely coated with sauce. Top with crushed chicharon (pork rinds), shrimp, and chopped green onions.
You may add some grated Parmesan cheese if desired.
Note 1. If the sauce gets too thick, just add a little water, about a half cup.