-
1
Place chicken broth, salt, fennel, onions, and chicken in a large pot and bring to a boil over high heat.
-
2
When it boils, reduce heat to low, cover, and simmer until chicken is tender and completely cooked, about 1 hour.
-
3
Remove chicken from liquid and place on a cooling rack set on a baking sheet to cool.
-
4
Reserve the cooking liquid for another use.
-
5
Melt 1 tablespoon butter in a large frying pan over medium heat.
-
6
When it foams, add 1/4 of the mushrooms.
-
7
Cook, stirring occasionally, until mushrooms are golden brown, about 10 minutes.
-
8
Remove from pan, season well with salt and freshly ground black pepper, and set aside.
-
9
Cook remaining mushrooms in 3 more batches, using 1 tablespoon of butter per batch.
-
10
When the chicken is cool enough to handle, remove skin and cut meat into 1-inch cubes.
-
11
Discard skin and bones, and reserve meat.
-
12
Heat oven to 375 degrees F and arrange rack in middle.
-
13
Combine half-and-half and milk in a medium saucepan and bring to a simmer over medium-low heat.
-
14
Once mixture simmers, reduce heat to low to keep warm.
-
15
Melt 10 tablespoons of butter over medium heat in a large Dutch oven or heavy-bottomed pot that is wider than it is tall.
-
16
When it foams, add leek and garlic, and cook until softened, about 2 minutes.
-
17
Season with salt.
-
18
Sift flour over the leek mixture and stir to combine.
-
19
Cook, stirring constantly, until flour is well incorporated and has lost its raw flavor, about 3 minutes.
-
20
Remove from heat; slowly add warm half-and-half and milk, stirring constantly until smooth.
-
21
Return to stove over medium heat and cook sauce until it simmers and begins to thicken, about 3 minutes.
-
22
Remove from heat and add the hot sauce, Parmiggiano-Reggiano, Emmentaler, and chopped thyme; stir until cheese melts.
-
23
Stir in the reserved chicken and mushrooms mixture and the frozen artichoke hearts; taste mixture and adjust seasoning if necessary.
-
24
Butter a 13-by-9-inch baking dish.
-
25
Spread the chicken-and-artichoke mixture in an even layer then evenly sprinkle breadcrumbs over top.
-
26
Bake, uncovered, until the edges are bubbling, breadcrumbs are browned, and casserole is heated through, about 30 minutes.
-
27
Allow casserole to sit for 5 minutes before serving.
