Place large, firm, ripe tomatoes in boiling water for a few minutes. Peel and cut each tomato in even-sized thick slices. Re-form tomatoes and place them in a rectangular or oval hors-d’œuvre dish.
Mix the next 8 ingredients to form a thick, green, well-flavoured dressing. Sandwich three-quarters of the dressing carefully between layers of each tomato. Chill.