Pound out chicken breasts between waxed paper, until about 1/2 inch thick.
In a large skillet over low heat melt butter, add garlic, cook for 1 minute. Add mushrooms,and salt, cook stirring for 3 minutes, then add spinach.
Cover and cook 3 minutes longer. Divide the mixture, leaving in pan, into 4 portions.
Mix parmesan cheese with basil, put on a plate.
Take chicken out, and place each portion of spinach mixture onto chicken, spreading out within an inch of sides. Sprinkle 1 Tbl. of cheese on top. Roll each piece up, tucking sides in slightly. Repeat with remaining chicken.
Preheat oven to 400.
Make sure Phyllo is room temperature. Cut 8 sheets of phyllo at a time in half, cutting on the longest side.
Using 4 halves per chicken roll, brush with melted butter, each piece, stacking as you go. Roll chicken, in more cheese mixture , then place on one end of buttered Phyllo. Fold up 2 sides, then roll to the end. repeat with the 3 remaining chicken rolls.
Using a glass casserole dish, set the rolls in pan. Cut slits on the top of each. Brush butter over top. Sprinkle tops with sesame seeds.