1. Preheat oven to 375°F (190°C).
2. On a lightly greased baking sheet, arrange chicken and beef livers. Bake in oven for 10 minutes, or until brown. Drain excess liquid from liver while baking.
3. In a large skillet, heat oil; add onions and saute until soft. Cook.
4. In a meat grinder or food processor, combine liver, onion, eggs, salt and pepper. Grind or chop with an on/off motion about 2 minutes, until roughly chopped.
5. Serve on toast topped with shredded lettuce.