Make the filling: Place the ground beef and onion into a large pot. Break up the ground meat into one even layer. Add enough water to just cover the beef and onion. Bring the mixture to a boil over medium-high heat and reduce the heat to a simmer. Cook until most of the water evaporates and the meat is completely cooked, about 20 minutes. Strain the meat and onion from any excess cooking liquids and discard the onions. Place the cooked beef and garlic cloves into a food processor. Pulse the mixture about 10 times or until the mixture is finely ground and uniform. Transfer into a large bowl. Add the salt, pepper, cumin and harissa and mix until combined well. Taste to adjust any seasoning. 

Make the harissa aioli: Whisk the garlic, mayonnaise, lemon juice, salt, and harissa in a bowl until combined well. Drizzle the olive oil on top. Set aside. 

Shape the cigars: Place the flour and water into a small bowl and mix until combined well. Set aside. Lay out a lumpia wrapper onto a clean surface. Cover the rest of the wrappers with a damp paper towel to prevent them from drying out. Dip your finger into the water and flour mixture and spread a thin layer of it around the edges of the wrapper to help seal the cigar once shaped. Place a heaping teaspoon of the beef mixture on the bottom third of the wrapper and shape the filling into a horizontal log. Fold the right and left edges of the wrapper over the edges of the filling and starting at the closed horizontal edge to you, roll up the wrapper until the beef cigar shape is formed. Transfer the cigar onto a large plate and repeat filling and shaping the rest of the cigars. 

Fry the cigars: Place about 1 inch of oil into a wide frying pan over medium-high heat. Once the oil is sizzling, gently place enough beef cigars to fit the pan without overcrowding. Fry the cigars until their bottoms are golden brown and flip to fry the other side until golden brown, about 1 ½ minutes per side. Transfer onto a paper towel-lined tray and continue frying the remaining cigars in batches adding more oil into the pan if needed.

Serve hot with a side of harissa aioli.