Step 1: Prepare the roast beef:
Season the beef roast liberally with salt and pepper. Allow it to come to room temperature for about an hour. Preheat your oven to 375°F (190°C). Place the beef in a roasting pan and roast for about 1 hour and 20 minutes or until the internal temperature reaches 135°F (for medium-rare). Remove from oven, cover with foil, and let rest for about 20 minutes.
Step 2: Make the Yorkshire pudding:
Increase the oven temperature to 450°F (230°C). In a bowl, whisk together 1 cup of flour, 4 eggs, 1 cup of milk, and a pinch of salt until smooth. Let the batter sit for at least 30 minutes. In a muffin tin or a large roasting pan, add a small amount of oil or beef drippings to each section and place in the oven until very hot, about 5 minutes. Pour the batter into the hot oil and bake for 20-25 minutes until the puddings have puffed up and are golden brown. Serve immediately with the roast beef.