In large skillet, cook onion and green pepper in salad dressing just until tender. Stir in mustard; remove from heat. Set aside.

Grease cookie sheet. In large bowl combine flour mixture with yeast from foil packet. Stir in Hot water, 2 T oil and egg until dough pulls away from sides of bowl. Turn dough out onto floured surface. With greased or floured hands, shape dough into a ball. Knead dough for 5 minutes until smooth. Sprinkle additional flour over surface to reduce stickiness. Cover with large bowl; let rest 5 minutes.

On lightly floured surface, roll dough to 16x14" rectangle. Arrange ham, salami and Swiss cheese lengthwise over half of dough, overlapping slices; sprinkle with cheddar cheese. Spread onion mixture over meats and cheeses. Fold remaining half of dough over filling. Pinch edges to seal; tuck ends under. Place on greased cookie sheet. Cover loosely with greased plastic wrap and cloth towel. Let rise in warm place (80 to 85F) 15 minutes.

Heat oven to 400F. Uncover dough. Brush with 1 T oil; sprinkle with poppy seed. Bake at 400F. for 15 to 20 minutes or until golden brown. Let stand 15 to 30 minutes before serving. Cut in half lengthwise, then make 10 crosswise cuts forming 20 slices.