- Remove tomato cores by slicing each tomato into ½-inch slices horizontally. Set aside the top and bottom slices of each tomato. Using a ring cutter, punch out the center of each tomato slice (creating a donut-like shape out of each tomato). Set aside the small center cutouts.
- Remove Italian sausage from casing and fill each green tomato slice to form a patty of sausage inside each tomato ring. Let sit in refrigerator for 2 hours or covered overnight.
- While tomato rings are cooling, rough-chop the reserved tomato centers and top and bottom slices. Place into mixing bowl.
- Place chopped herbs in a mixing bowl with chopped tomato and season mixture with oil, white balsamic, and salt. Set aside to marinate.
- Add buttermilk to a bowl and pour masa into separate shallow baking dish. Meanwhile, heat oil in a pan over medium-high heat.
- Carefully dredge each tomato patty in masa, then in buttermilk, then in masa again.
- Pan fry tomato patties in oil until golden brown on each side and until sausage is cooked through. Remove, place on paper towels, and season with salt. Transfer to 4−6 plates to serve.
- Gently simmer water in a saucepan. Add white vinegar. Crack an egg into a small bowl. Gently stir water to create some movement then place egg in pot to poach. Wait about 3−4 minutes, then pull egg from liquid and place on top of tomato slice. Repeat with all eggs.
- Garnish with marinated green tomato and serve immediately.