Stuffed Zucchini Gratin
By Emma
Certified Culinary Professional
•
Recipe tested & approved
Ground beef cooked in olive oil with onions, mushrooms, and garlic, mixed with broth and breadcrumbs, stuffed into hollowed zucchini boats. Topped with tomato sauce and shredded mozzarella, baked until bubbling and tender-crisp. Six servings. A balance of savory and slight tang from tomato, crusty cheese golden on edges. Easy to tweak with pantry staples.
Prep:
35 min
Cook:
48 min
Total:
Servings:
6 servings
#French-inspired
#baked dishes
#vegetable stuffing
#ground beef recipes
#mozzarella cheese
Ever wrestled with watery stuffed zucchini? Happens when filling too loose or zucchini soggy from watery flesh. Learned the hard way, now I keep zucchini walls thick and dry after hollowing. The filling, rich ground beef browned with onion, garlic and mushrooms, gets soaked in broth before breadcrumbs; this binds without mush. The key — sizzle and color upfront. Then, the sauce dresses everything, followed by a blanket of mozzarella that crisps and browns into a nutty crust. Timing’s not sacred—watch for bubbling and zucchini that yields under a fork but retains snap. Serve warm, letting the melded flavors soak in after baking. Every bite a mix of savory, mild tang, and oozy cheese, coaxed out in oven’s slow heat.
Ingredients
- 240 g lean ground beef
- 30 ml olive oil
- 1 small onion finely chopped
- 115 g button mushrooms chopped
- 2 cloves garlic minced
- 125 ml chicken broth (can use vegetable broth)
- 60 ml plain breadcrumbs
- 4 to 6 large zucchini
- 375 ml crushed tomatoes (canned or fresh puréed)
- 375 ml shredded mozzarella cheese
- Salt and pepper
About the ingredients
Lean ground beef works best for balance—too fatty and dish becomes greasy. Olive oil heats faster for good browning. Onions should be finely chopped to melt into filling, while mushrooms add earthy moisture; button mushrooms preferred but cremini or shiitake can swap in for depth. Garlic essential, don’t skimp or it’s flat. Chicken broth choice impacts outcome; homemade adds richness but store-bought fine too; vegetable broth is fine for pescatarians. Breadcrumbs bind but can switch with crushed crackers or gluten-free crumbs to suit. Zucchini size matters, bigger hold more filling but risk more water release. Sauce tomato can be canned crushed or fresh puréed tomatoes—avoid watery juices. Mozzarella with good melt preferred; pre-shredded works but sometimes has anti-caking additives that hamper browning. Salt and pepper to taste, adjust at both cooking phases—season meat mix well, then taste after adding broth and breadcrumbs.
Method
- Heat oil in a heavy pan on medium-high. Brown beef till edges caramelize; don’t overcrowd pan or it steams. Toss in onion, garlic and mushrooms. Stir often – listen for sizzle. Cook till soft, fragrant, and starting to brown. Season generously. Pour in broth to deglaze, scraping stuck bits with wooden spoon – that’s flavor. Stir in breadcrumbs; they soak the juices and bulk filling. Off heat let cool slightly, saves mess later.
- Position oven rack mid-level. Preheat to 175 C (350 F). Give yourself prep space.
- Trim zucchini ends. Using a melon baller or spoon, hollow out center, leaving about 2.5 cm thick walls. Don’t pierce skin or boat leaks. Keep hollowed flesh for another use or discard. Wipe zucchini dry to avoid watery bake.
- Fill zucchini boats by hand, pressing filling to pack but not squash. Place side by side in a ceramic gratin dish approx 33x23 cm. Pour tomato sauce evenly over boats; mixture seeps into gaps. Top uniformly with mozzarella. Don’t overdo cheese or it becomes gloopy instead of golden crisp.
- Bake around 48 minutes. Check zucchini texture by poking skin with knife - should feel tender but not mushy; filling bubbling and cheese browned edges tell you it’s good. If cheese browns too fast, tent loosely with foil.
- Cool 8-10 minutes before serving. Juices settle and flavors marry better. Cut into halves or slices or serve whole. Use kitchen towel to hold zucchini if hot. Plate with rustic bread or salad.
Cooking tips
Browning the beef first is non-negotiable—no color means no depth. Stirring frequently prevents burning onions or garlic which turn bitter fast. When deglazing with broth, scrape bottom to dissolve caramelized bits—it’s where flavor lives. Breadcrumbs help hold filling’s shape; add gradually and test texture—too dry becomes crumbly, too wet soggy. Make boats with thick zucchini flesh to stop collapse. Use a melon baller for clean cavities—less mess. Packing the filling tighter ensures no air pockets but don’t pack to stiffness—the filling should still be moist, so juices escape into sauce. Sauce distribution matters; too much suffocates zucchini, too little dries. Cheese layer not only topping but traps heat, creating that crust. During baking, check after 40 minutes—the cheese color and zucchini firmness guide doneness better than clock. Letting the dish rest post-oven lets juices redistribute; try cutting one open after resting to see that mix of runny and firm textures—ideal. Serving hot can lose shape, warm is best. If cheese bubbles excessively or burns early, tent with foil and reduce oven temp slightly. If zucchini seems too watery, roast raw slices separately to dry before stuffing next time.
Chef's notes
- 💡 Brown beef on medium-high heat; hear that sizzle. Don’t overcrowd pan, or you steam meat instead of caramelizing. Color adds deep flavor; no color, no punch. Stir onion and garlic often; burnt garlic turns bitter quick.
- 💡 Use broth to deglaze pan; scraping bits off bottom releases trapped flavors. Add breadcrumbs gradually. Too much makes filling dry, too little soggy. Test texture by pressing, filling should hold together but still moist, juices need space to move.
- 💡 Hollow zucchini thick; at least 2.5 cm walls. Thin ones collapse in oven. Dry flesh well after scooping to avoid watery bake. Use melon baller for clean hollow — less mess, better shape retains filling snugly without leaks.
- 💡 Spread tomato sauce evenly; too much drowns zucchini and filling. Cheese layer traps heat causing crust formation. Don’t pile cheese on thick or it gets gloopy, not crisp. Look for edges browning for doneness signal, foil tent if burning early.
- 💡 Bake about 48 minutes but check often after 40 min. Poke zucchini skin with knife; tender but not mushy. Cheese bubbling and browning cues done. Let rest post-oven to settle juices; cutting right away loses that mixed texture of runny and firm.
Common questions
Can I substitute ground beef?
Sure. Ground turkey or chicken work but less fat means dry. Add oil or moisture fillers like grated zucchini or mushrooms finely chopped. Vegan? Use lentils or mushrooms, add breadcrumbs extra to bind well.
What if zucchini is watery?
Dry hollowed flesh well. Use bigger zucchini with thick walls. You can roast slices first to pull moisture. Avoid watery tomato sauces; strain if needed. Let filling drain on paper towel before stuffing.
How to avoid soggy filling?
Brown beef thoroughly. Don’t overcrowd pan, liquid escapes easily. Gradually add broth and breadcrumbs. If filling too wet add more breadcrumbs/crackers. Pack filling firmly but not tight; air pockets cause sogginess.
Best way to store leftovers?
Cool completely. Store in airtight container fridge up to 3 days. Reheat oven or microwave. Can freeze but texture changes; better to freeze filling separately, thaw before stuffing fresh zucchini.
