Preheat the grill and set the oven rack at about 15cm from the heat source. Place the sausage links onto a baking pan and grill in the preheated oven until the sausages are crispy on the outside and no longer pink on the inside, about 8 minutes. Turn the sausages once as they cook.
Bring a large pot of lightly salted water to a boil. Add the bow-tie pasta and cook until al dente, 8 to 10 minutes. Drain and return to the pot along with the spinach; keep warm over medium-low heat.
Heat the olive oil in a separate pot over medium heat, stir in the garlic and cook until the garlic softens and the aroma mellows, about 3 minutes. Add the Alfredo sauce and black pepper then bring to a simmer over medium-high heat. Cut the cooked sausage into bite-sized pieces and add to the simmering Alfredo sauce along with the pasta and spinach. Stir until the pasta is hot and well coated with the sauce.