Combine sausage links and 1 cup water in a large skillet; bring to a boil, about 5 minutes. Cover, reduce heat, and simmer until juices run clear, about 15 minutes. Drain water from skillet.

Cook links in the skillet, stirring frequently, until browned, 2 to 4 minutes. Remove from skillet, cool, and cut into 1/2-inch diagonal slices. Wipe skillet clean using a paper towel.

Heat skillet over medium heat; add olive oil. Add onion; cook until tender but not brown, 3 to 5 minutes. Add garlic; cook until fragrant, about 30 seconds. Stir in tomatoes, tomato paste, wine, oregano, and red pepper flakes. Stir in bell pepper and cooked sausage. Bring to a boil, about 5 minutes. Reduce heat, cover, and simmer until reaches desired thickness, about 20 minutes.

Meanwhile, fill a large pot with lightly salted water and bring to a rolling boil; stir in tortellini, reduce heat slightly, and return to a boil. Cook, uncovered, stirring occasionally, until tortellini float to the top, filling is hot, and tender but still firm to the bite, 5 to 10 minutes. Drain.