Step 1: Add the Beef and Onion - Start by browning the ground beef in a skillet on the stove. Once the beef is cooked through, drain any excess grease. Transfer the browned beef to the slow cooker along with the diced onion.
Step 2: Add the Sauce Ingredients - Sprinkle the taco seasoning over the beef mixture. Add the drained diced tomatoes with green chilies, beef broth, and heavy cream. Stir everything together so the flavors begin blending.
Step 3: Slow Cook the Base - Cover the slow cooker and cook on low for about three hours. During this time the onions soften and the sauce develops rich taco flavor.
Step 4: Add the Tortellini - About thirty to forty minutes before serving, stir the refrigerated cheese tortellini into the slow cooker. Make sure the pasta is coated in the sauce so it cooks evenly.
Step 5: Melt the Cheese - Once the tortellini is tender, add the shredded Mexican blend cheese and stir until it melts into the sauce.
Step 6: Garnish and Serve - Spoon the taco tortellini into bowls and top with sliced scallions or fresh tomatoes if you like a little extra freshness. Then gather everyone around the table and enjoy.