Preheat the oven to 375°F (190°C).
Sauté the onion and garlic in olive oil over medium heat until soft.
In a bowl, combine the chopped shrimp, lump crab, cream cheese, Old Bay seasoning, and lemon juice.
Incorporate the sautéed onion and garlic into the seafood mixture.
Slice the biscuits in half horizontally and place them on a baking sheet.
Spoon the seafood mixture onto the bottom half of each biscuit.
Top each filled biscuit half with shredded cheese.
Place the baking sheet in the preheated oven and bake for 15-20 minutes.
Remove from the oven, let cool slightly, and serve warm.