Step 1 Microwave capsicum, shallots, mushrooms and baby spinach on high for 2 minutes, or until tender.
Step 2 Meanwhile, place a medium frying pan face down on a sheet of baking paper. Use a pencil to trace circumference onto paper. Cut out circle and place in pan so edge sits about 2cm above base. (Repeat to make 4 paper circles.)
Step 3 Place pan over medium heat. Put 2 of the eggs and 1/4 teaspoon of the curry powder in a medium bowl; whisk with 1 tablespoon water until well combined.
Step 4 Pour egg mixture over paper circle in pan, tilting carefully so mixture spreads to edge; cook for 5 minutes, or until almost set.
Step 5 Arrange one-quarter of the cooked veg evenly over one side (half) of the egg. Scatter veg with one-quarter of the grated cheese. Once egg has set, flip egg side over vegies to form a semicircle omelette and cook for 2–3 more minutes, or until cheese melts.
Step 6 Slide omelette out of frying pan. Peel off paper circle carefully and discard. Put omelette on a serving plate. Make 3 more omelettes with remaining paper and ingredients.