Chicken Asparagus Lasagna

2 1/2 pounds skinless boneless chicken breasts
salt and pepper - to taste
3 Tbsp. olive oil
3 pounds fresh asparagus - trimmed
1/2 cup butter
1/2 cup all-purpose flour
2 1/2 cups whole milk
2 1/2 cups chicken stock
2 medium yellow onions - cut in small dice
1 1/2 Tbsp. minced garlic
2 Tbsp. finely chopped fresh thyme
1/4 cup finely chopped flat leaf parsley
kosher salt - to taste
freshly ground black pepper - to taste
1 1/2 pounds lasagna noodles - cooked and drained
1/2 pound Asiago cheese - grated
3/4 pound monterey jack cheese - grated

Trim chicken, season with salt, pepper and olive oil; let marinate about 30 minutes. Grill on each side and finish in 350�F oven until just done (about 12 minutes). Cool and cut into 1/2 inch dice.

Blanch asparagus in boiling chicken stock for 1 minute, cool and grill lightly (can use a cast-iron skillet). Cool, cut on bias into 1/2-inch pieces, reserving 15 tips about 1 1/4 inches long. Add asparagus pieces to chicken.

Saut� onions, garlic and thyme over medium heat in butter for 3 to 4 minutes until softened. Stir in flour to form a roux and continue to cook, stirring, for 4 to 5 minutes over medium-low heat.

Meanwhile, bring chicken stock back to a boil, add milk and reduce heat to medium. Add milk mixture to roux, 1 cup at a time, stirring constantly.

Simmer sauce for 10 minutes, stirring often to avoid scorching. Season with kosher salt and pepper. Combine with chicken, asparagus and parsley.

For lasagna: In a large lasagna pan or two 9x13 inch baking dishes, layer chicken and asparagus with sauce, lasagna noodles, grated Asiago and jack cheese, repeating layers as necessary. Garnish with reserved asparagus tips.

Can be made ahead to this point and refrigerated.

Bake at 325�F for 30 to 40 minutes or longer if it has been refrigerated. Serve hot.