How many servings does this recipe make?

This recipe makes 4 servings. You can adjust the portion size directly on this page.

What ingredients do I need for Oyster-Spinach Casserole?

You need 14 ingredients. The key ingredients include: 1 c. sliced fresh mushrooms, 1/4 c. minced green onions, 1 clove garlic, minced, 2 (10 oz.) pkg. frozen chopped spinach, and more.

Is Oyster-Spinach Casserole suitable as seafood?

Yes, Oyster-Spinach Casserole falls under the Seafood category and is a great choice for this type of meal.

How do I store leftover Oyster-Spinach Casserole?

Store leftovers in an airtight container in the refrigerator for up to 3–4 days. Reheat gently before serving.

Oyster-Spinach Casserole Recipe

Name: Oyster-Spinach Casserole
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 1 c. sliced fresh mushrooms; 1/4 c. minced green onions; 1 clove garlic, minced; 2 (10 oz.) pkg. frozen chopped spinach; 1 Tbsp. margarine; 2 Tbsp. all-purpose flour; 1 c. skim milk; 1 tsp. lemon juice; 1/4 tsp. ground nutmeg; dash of white pepper; 2 (12 oz.) containers Select oysters, drained and rinsed; 1/4 c. grated Parmesan cheese; 2 Tbsp. fine, dry breadcrumbs; pimiento strips (optional)

Try this homemade Oyster-Spinach Casserole recipe the whole family will love. Made with mushrooms, green onions, clove garlic and spinach. Easy step-by-…

This Oyster-Spinach Casserole relies on simple, everyday ingredients such as sliced fresh mushrooms, minced green onions, garlic, minced and margarine. It comes together quickly and makes 4 servings, at about 175 kcal each. The step-by-step instructions below are written to be easy to follow, even on a busy day.

It's versatile enough for an easy weeknight dinner yet satisfying enough for guests at the weekend. Serve it with your favorite sides, and keep any leftovers for a quick meal the next day.

Updated Jun 30, 2026

Serves 4 Seafood

Tips for the best results

Read through all the steps once before you start and measure out your ingredients first — it makes everything go more smoothly.
Taste as you go and adjust the seasoning before serving.
Avoid overcrowding the pan — cook in batches if needed for the best texture.
Let the dish rest for a few minutes before serving so the flavors settle.
Store leftovers in an airtight container in the fridge and enjoy within a few days.

Variations & substitutions

A good 1:1 gluten-free flour blend works well if you need a gluten-free version.

No specific allergen information. Please check the ingredient list for possible allergens.

My Personal Notes

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Oyster-Spinach Casserole

Tips for the best results

Variations & substitutions

My Personal Notes

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