Warm oil or melt the butter in a medium non-stick pan over medium-low heat. Add the chopped sun-dried tomatoes and cook until warmed through and fragrant, about 30 seconds.

Crack eggs into a bowl, add a pinch of salt and whisk until well blended.

Pour the eggs into the skillet and immediately use a silicone spatula to swirl in small circles around the pan, without stopping, until the eggs look slightly thickened and very small curds begin to form, about 30 seconds.

Add the spinach leaves, and then change from making circles to making long sweeps across the pan until you see larger, creamy curds and the spinach starts to turn bright green and wilts; about 20 seconds.

When the eggs are softly set and slightly runny in places, remove the pan from the heat and leave for a few seconds to finish cooking. Give a final stir and assemble burritos.

Place tortillas down onto a flat work surface. Spoon half of the egg and spinach mixture down the center of each tortilla. Divide the cheese between each burrito and scatter it on top of the egg.

Fold the sides of the tortillas over the filling, and then tightly roll the end closest to you up and around the filling, pushing any bits that fall out back into the middle of the burrito. Place the burrito seam-side down.

Wrap and refrigerate up to 3 days or tightly wrap each burrito individually in foil, and then place into a resealable freezer bag or container. Freeze up to 3 months.

To reheat frozen burritos, unwrap the burrito, place onto a microwavable plate, cover with a paper towel and microwave for one minute, flip and microwave another 1 to 2 minutes or until the center is hot. Enjoy immediately or add a crunchy exterior by following the directions for toasted burritos below.

Heat a medium skillet over medium heat. Place burritos seam-side down into the hot pan and toast until the underside is lightly browned and crisp, 20 to 60 seconds. Rotate the burrito and repeat on all sides.