Place the tortellini in plenty of boiling salted water and cook for 15-20 minutes. In the meantime, clean, wash and drain the peppers and spring onions. Dice the peppers, cut the spring onions into fine rings.
Wash the tomatoes, drain and cut in half. Cut cabanossi into thin slices. Peel and finely chop the onion. Briefly boil half of the onion, stock, vinegar, oil, about salt and pepper.
Place the tortellini on a sieve, rinse under cold water and drain well. Place the tortellini in a large bowl, mix with the broth vinaigrette, allow to cool and soak. Meanwhile, for the sauce, roast pine nuts in a pan without fat and let them cool down.
Drain dried tomatoes on kitchen paper, dice or chop them finely. Wash the basil, dab dry and cut into fine strips, except for a little to garnish. Mix yoghurt, sour cream, dried tomatoes, 2/3 of the pine nuts, basil and remaining diced onion.
Season the sauce with salt and pepper. Mix cooled tortellini, peppers, spring onions, tomatoes and cabanossi with the sauce. Arrange on a large platter, sprinkle with remaining pine nuts and garnish with basil.