In a large pot on medium heat melt coconut oil. Add onion, garlic and jalapeño. Once onion begins to soften, add flour and cook until slightly bubbly. Stream in broth, stirring constantly until liquid is cloudy and begins to thicken. Cover and bring to a boil.
Once boiling, add shells and press down to ensure pasta is completely covered. Bring to a boil, then reduce to simmer and cover. Cook according to package instructions or until desired tenderness.
Remove from heat and stir in heavy cream, lemon juice, lemon zest and cheese. Continue stirring until cheese has melted and is evenly distributed, adding more if desired.
Season with salt and pepper to taste. Stir in cilantro and serve.