Preheat oven to 350°F. Coat a 11×7 baking dish with nonstick spray. Set aside.
In a skillet heat the olive oil over medium-high. Add in the sausage and cook until crumbly and no longer pink, about 7 minutes. Remove the sausage from the skillet and place in a bowl. Set aside. Drain the grease form the pan.
Turn the heat down to medium, and melt the butter in the same skillet. Whisk in the flour, and cook for 2 minutes, constantly whisking.
Slowly add the milk, salt and pepper while constantly whisking. Bring mixture to a boil and continue cooking for 3-4 minutes, until the gravy thickens slightly. Add the sausage back to the skillet and stir to combine. Remove from heat.
Divide the biscuits in half lengthwise. Place 8 halves in the bottom of the prepared baking dish. Top with half of the sausage gravy, half of the cheese, and half of the green onions. Repeat the process.