1. Steam Swiss chard leaves for 1-1/2 minutes; steam Swiss chard ribs for 2 minutes. Heat olive oil in a nonstick sauti pan over medium heat. Add garlic, sauti 30 seconds.
2. Add Swiss chard leaves and ribs, and tomatoes; sauti until warm, about 1-1/2 minutes.
3. Season to taste with salt and black pepper; keep warm.
4. Beat eggs in a large mixing bowl with a whisk, season to taste with salt and white pepper.
5. Melt the butter in a small, nonstick sauti pan over medium heat. Pour eggs into pan, do not stir; let cook until eggs begin to set, about 2 minutes.
6. Stir the eggs continuously with a heat resistant rubber spatula, scraping eggs from sides and bottom of pan as you stir until almost set, about 30 seconds.
7. Using the spatula, distribute eggs evenly in pan, flattening the surface of eggs and filling in any holes; cook until almost set, about 30 seconds.
8. With the handle of pan on left, gently fold top third of the omelet over middle of omelet using spatula.
9. Grab handle of pan from underneath, tilt pan to 45 degrees angle and place over plate; loosen omelet from pan with spatula; using the pan, slide the omelet onto plate while folding top two-thirds (folded portion) over the bottom third, creating a trifold.
10: Using a small, sharp knife, cut a slit into the top of and almost through all layers of the omelet, leaving 1 uncut on each side of the slit.
11. Spoon filling into slit of omelet, and sprinkle with cheese and chives; drizzle plate with balsamic vinegar reduction.
Combine vinegar and sugar in a small nonstick sauti pan over medium-low heat. Let reduce to a thick consistency, about 13 minutes; cool at room temperature.