Defrost the spinach in the microwave, wring it dry and separate the leaves.
Meanwhile, bring a large pot of water to a boil, salt it, add the tortellini and cook according to package directions. Drain and let cool.
In a large skillet, heat the EVOO, two turns of the pan, and butter over medium heat. Add the shallot and garlic and cook, stirring, for two minutes. Add the artichokes and spinach; season with salt and pepper and a hint of freshly grated nutmeg.
Add the tuna and pasta to a bowl. Top with the spinach and artichokes. Dress with the lemon juice and thyme. Serve or refrigerate for later.