Preheat the grill to high. Place the halved tomatoes on a baking tray. Place under the grill for 10-15 minutes, until golden.
Meanwhile, bring a pan of cold water to the boil, then turn down to a gentle simmer and add 1 tablespoon of vinegar. Crack 2 eggs into the water and poach for 3 minutes for soft-boiled eggs. Boil longer for a harder yolk.
Repeat with 2 more eggs. Meanwhile, toast the muffins. Spread with I Can’t Believe It’s Not Butter, top with the eggs and serve with the tomatoes.