1. In a large pot, heat olive oil over medium heat. Saute onion, shallot, garlic, and leeks until opaque, but not yet browning. Add mixed grains and saute until grain is slightly toasted and aromatics begin to brown. Add water and simmer until reduced by half.
2. Add vegetables, lemon, and stock. Simmer until vegetables and rice are tender, about 25-30 minutes. Add salt and pepper to taste. Just before removing from heat add minced parsley.
3. Serve warm with bread and cheese, if desired.
Makes a very large pot of soup. This soup freezes well.