Creamy, cheesy, and packed with fresh basil flavor—this low-carb casserole is about to become your weeknight hero.

Why This Recipe Works

One-pan wonder: Everything bakes in a single dish, so cleanup is a breeze.
Meal-prep friendly: Tastes even better the next day—perfect for Sunday prep.
Kid-approved: My pesto-picky 9-year-old asks for seconds.
Freezer hero: Assemble, wrap, and freeze for up to 3 months.
Macro-balanced: 5 g net carbs, 38 g protein, and healthy fats to keep you in ketosis.
Customizable topping: Choose almond-flour crunch or pork-rind crackle.

Ingredients You'll Need

Great casseroles start with great building blocks. Below I’ve listed exactly what goes into my keto pesto chicken casserole, plus the brands I trust and the swaps I’ve tested so you can shop with confidence.

Protein

1 ½ lb (680 g) boneless skinless chicken thighs – Thighs stay juicy after a long bake; if you prefer breast, reduce cooking time by 10 min. Look for air-chilled organic thighs—no added water so the casserole won’t get soupy.

Vegetables

1 medium zucchini (250 g) – Adds moisture without many carbs. Choose firm, small zucchini; giant ones can be bitter and spongy.

1 cup cherry tomatoes – A pop of color and sweetness. If you’re strict keto, swap for ½ cup diced bell pepper (2 g fewer carbs).

Sauce & Cheese

¾ cup basil pesto – I make a double batch of my 5-Minute Blender Pesto in summer and freeze ¼-cup pucks. Store-bought is fine; look for one packed in olive oil, not canola, and count 2 g carbs per ¼ cup.

4 oz cream cheese, cubed – Creates silky body. Soften 20 s in the microwave so it melts evenly.

1 cup shredded mozzarella – Low-moisture, part-skim melts best without puddles.

½ cup grated Parmesan – Buy the refrigerated stuff, not the shelf-stable can; the flavor difference is night and day.

Topping Choices (pick ONE)

Pantry Staples

Garlic, sea salt, black pepper, and red-pepper flakes you already own. That’s it—no exotic binders or starches.

How to Make Keto Pesto Chicken Casserole with Topping

Preheat & prep pan

Set oven to 400 °F (200 °C). Lightly grease a 2-qt (1.9 L) casserole or 9-inch square baking dish. A ceramic dish retains heat beautifully, but metal works—just drop the temp to 375 °F to prevent over-browning.

Season & sear the chicken

Pat thighs dry; sprinkle with 1 tsp salt, ½ tsp pepper, and ¼ tsp red-pepper flakes. Warm 1 Tbsp olive oil in a skillet over medium-high. Sear chicken 2 min per side—no need to cook through; you just want golden edges that will stand up to the bake.

Build the vegetable layer

While the chicken rests, toss zucchini half-moons and halved tomatoes with the rendered chicken fat plus a pinch of salt. Spread them in the casserole; they’ll protect the bottom from drying out.

Make the pesto cream

In the same skillet (don’t wipe it out—those browned bits = flavor) melt cream cheese with ¼ cup water over low. Whisk in pesto until silky. Taste; add salt if your pesto is mellow.

Assemble

Lay seared chicken on top of vegetables, pour pesto cream evenly, then sprinkle mozzarella and Parmesan. The order matters: cheese on top prevents the pesto from browning too fast.

Add topping

Stir chosen topping ingredients in a small bowl until moist crumbs form; scatter over cheese. Press lightly so it adheres but still looks rustic.

Bake

Slide onto middle rack and bake 22–25 min, until topping is golden and internal temp hits 165 °F (74 °C). If you like an extra-crispy lid, broil 1–2 min at the end—watch closely!

Rest & serve

Let stand 10 min so the sauce thickens; serve scooped straight from the dish. Garnish with extra basil ribbons and a crack of pepper for restaurant vibes.

Expert Tips

Don’t skip the sear

Maillard browning equals flavor insurance under all that creamy sauce. Even 90 seconds per side makes a difference.

Zucchini moisture hack

Toss coins with ½ tsp salt, let sit 10 min, then blot; this prevents a watery bake if your squash is extra-plump.

Freeze smart

Wrap tightly in foil then plastic. Thaw 24 h in fridge, add 10 min to bake time, and refresh topping under broiler.

Dairy-light?

Swap cream cheese for ½ cup coconut cream and use nutritional yeast + ⅓ cup vegan mozzarella—still keto, still luscious.

Variations to Try

Storage Tips

Refrigerate: Cool completely, cover tightly, and refrigerate up to 5 days. Reheat single portions in the microwave 90 s with a damp paper towel over the top to re-steam the topping.

Freeze: As noted above, freeze pre-bake for best texture. If freezing leftovers, expect the topping to soften slightly—refresh under broiler.

Make-ahead: Assemble through Step 6, cover, and refrigerate up to 24 h. Add 5 min to bake time from cold.

Repurpose: Chop leftover chicken and veggies, stir in an extra splash of cream, and use as a stuffing for bell peppers or omelets.

Frequently Asked Questions

Absolutely—use 3 cups shredded meat folded in during Step 5. Skip the sear and reduce bake time to 15 min since the chicken is already cooked.

Traditional pesto (basil, pine nuts, olive oil, Parmesan, garlic) is naturally low-carb—about 1 g net carbs per tablespoon. Just watch brands that bulk up with potato starch or sugar.

Ovens run hot. Cover loosely with foil halfway through baking and position rack lower. Also, broil only 60 s max.

Yes—use a 9×13-inch pan. Bake 28–30 min. For topping, 1.5× the amounts; any more and it stays loose.

A crisp arugula salad with lemon vinaigrette cuts the richness. For extra fat, serve alongside roasted asparagus drizzled with herb butter.