Start by patting the beef tenderloin dry with paper towels so you get a better sear. Use a sharp chef's knife to cut the meat into 1.5-inch cubes. Try to keep them as uniform as possible so they cook at the same rate. (I tried using smaller 1-inch cubes once, they overcooked before I could even get the butter in the pan. Stick to the 1.5-inch size for the best medium-rare center.) Season the cubes heavily with sea salt and cracked black pepper on all sides. This salt helps draw out moisture but it also creates that beautiful crust we want later. Cut the meat into uniform pieces, it ensures every bite reaches 135°F at the exact same time.

Heat 2 tablespoons of olive oil in a 12-inch cast iron skillet over medium-high heat (about 7 on a 10-dial) until the oil shimmers. Carefully place the beef cubes in the pan. Make sure you don't crowd them so the heat stays high. Sear the meat for exactly 2 minutes per side without moving them. You'll hear a loud sizzling sound and smell the savory beef aroma. The edges will turn a deep mahogany and a thick crust will form on the surface. Don't move the meat too early or the crust will tear off and stick to the pan. Sear on high heat, the Maillard reaction creates all the flavor for our sauce later.

Turn the heat down to medium (about 5 on the dial) and add 4 tablespoons of unsalted butter and 4 cloves of minced garlic. Swirl the pan gently to melt the butter and move the garlic around so it doesn't burn. Sauté for about 60 to 90 seconds until the butter starts to foam and turns slightly golden. You'll smell the garlic toast right when it's ready. If you love this , it's very similar to how I prep the base for my Shepherd’s Pie. Watch the garlic closely because it turns bitter the second it goes past golden brown. Use medium heat, it keeps the butter solids from burning while the garlic infuses.

Add 1/2 cup of heavy cream and 1 cup of cooked cheese tortellini to the skillet. Stir gently with a wooden spoon for 2 to 3 minutes until the sauce thickens and coats the back of the spoon. Toss in a handful of chopped fresh parsley right at the end. (I once tried using milk instead of cream. The sauce was way too thin and didn't cling to the pasta, stick with the heavy cream for that restaurant-style finish.) The sauce will turn a light ivory color and the tortellini will look glossy and fully coated. If you miss this window and cook too long, the cream might break and look greasy. Finish with heavy cream, the fat emulsifies with the beef juices to create a smooth sauce.