Lightly spray 2 rimmed cookie sheets and pour 1/2 of cereals, nuts and crackers on each pan.  Toss around to mix.

Mix olive oil with Worcestershire sauce and stir well to blend.  Slowly pour sauce over all.

Gently mix sauce and cereal mixture by using a large serving spoon to gently fold ingredients over each other until all the pieces are coated.  If mixture seems dry, mix additional olive oil and Worcestershire and pour over cereal mix. Spread into an even layer in pans and sprinkle with seasoning salt.

Bake at 275 degrees for 20 minutes.  Stir, and continue cooking for another 15-20 minutes.

Transfer Chex mixture to a large area covered with paper towels and let mixture cool.  This only takes a few minutes.

Transfer mix into a large bowl or container and stir in M & Ms and white chocolate chips.  Place into jars or gift bags for giving or store in tightly covered containers.