Seaweed Pasta with Vegan Scallops

Seaweed pasta is what happens when buttered noodles meet their umami era—briny, savory, and deeply satisfying. The seaweed-matcha butter brings richness with a little edge, and pan-seared vegan scallops round it all out with texture and depth that make this feel comforting, but far from ordinary.

This seaweed pasta is doing the absolute most—with only a handful of ingredients. Tossed in a buttery blend of matcha and ochazuke wakame seasoning (more on that in a sec), it delivers a savory depth that feels fancy without being fussy. Pan-seared vegan scallops bring a golden edge and meaty bite that’s simple, bold, and just a little unexpected in the best way.

It all comes together in about 45 minutes, with just seven ingredients, and is ready to drop an umami bomb on your weeknight dinner plans. You may not already have matcha or wakame on hand, but they’re absolutely worth a trip to your nearest Asian or online market. Let’s get ready to find that perfect sweet spot between effortless and impressive!

Why You’ll Love This Seaweed Pasta

This is pasta night, but with a twist. Buttered noodles? Yes please. Seaweed butter gives everything a briny, savory, buttery depth, clinging to pasta—or noodles, if that’s your vibe. If your go-to pasta lineup could use a little oomph, this dish brings something totally new—and deliciously unexpected—to the table. Here’s more reasons to love it:

• Minimal ingredients, major flavor. Just seven ingredients come together in a way that feels new and fresh.
• Seaweed butter = instant umami upgrade. That blend of matcha and ochazuke wakame gives the butter a complex, salty depth that clings to noodles in all the right ways.
• Crisped-up vegan scallops that steal the show. Seared king oyster mushrooms look fancy and taste even better—meaty, golden, and tender with a perfect bite.
• Spaghetti, ramen, soba—your call. Seaweed butter works its magic on just about any noodle, so use what you love (or what’s in your pantry).
• The secret’s in the sauce. This isn’t marinara or olive oil territory. It’s savory, sea-salty, and full of oceanic flavor.

Key Ingredients

Each ingredient in this dish is bringing it without requiring a lot. The flavors here are bold but balanced, with richness from the butter, depth from the seaweed, and just enough edge from the matcha to keep it interesting. Here’s what you’ll need:

• King oyster mushrooms: Scallops, but make them plant-based. Their thick stems sear up beautifully with a golden crust and tender interior, making them the perfect stand-in for traditional scallops—minus the seafood.
• Cultured vegan butter: This is the base for our seaweed butter, giving it richness and body. Cultured butter brings a tangy, slightly fermented edge that plays especially well with umami flavors like matcha and seaweed. I used Miyoko’s brand here.
• Ochazuke wakame: A savory Japanese seasoning made primarily of dried seaweed, rice crackers, and salt. It’s typically used as a topping for ochazuke—a comforting Japanese dish made by pouring hot tea or dashi over cooked rice. In this recipe, it’s ground and stirred into butter, creating a quick shortcut to deep, layered umami (New to it? Check out the tip box below).
• Matcha powder: It might seem out of left field, but matcha totally works here. It deepens the color of the butter and adds a grassy, slightly bitter note that keeps the richness in check.
• Spaghetti (or noodles!): The butter clings best to long, slurpable noodles like spaghetti, soba, or ramen. Use what you have—this butter plays well with all of them.
• Black and white sesame seeds: A final sprinkle for contrast and a subtle nuttiness. They add texture and tie everything together with just a little visual flair.

Substitutions & Variations

This seaweed pasta is flexible, flavorful, and easy to vibe with what you’ve got on hand. The core flavors—umami-rich butter, crisped mushrooms, and slurpable noodles—stay the same, but there’s room to play around the edges. Here are a few ways to make it work for your kitchen and your pantry:

• Noodle swap: Spaghetti is classic, but soba, ramen, or udon are all great choices. Just aim for something long and sturdy enough to carry the seaweed butter.
• Vegan scallop alternative: No king oyster mushrooms? Try seared tofu for texture, or charred broccolini for a bitter, earthy note. Any other mushroom like shiitake, oyster, cremini, or even portobello will work—just give them a good sear for a contrast to the noodle texture.
• Butter matters: Cultured vegan butter gives the seaweed-matcha blend extra depth. Miyoko’s is our go-to, but if regular vegan butter will still work—it will just a bit less tangy.
• Matcha tips: You don’t need fancy matcha for this—just look for a culinary-grade or cooking-grade option, which is usually more robust and slightly bitter (perfect for savory recipes like this). You can usually find it online or in the tea section of Asian grocery stores.
• No ochazuke wakame? A furikake blend with seaweed and sesame (check the label for bonito flakes) makes a decent substitute. It won’t have quite the same depth, but it’ll still bring plenty of savory flavor with a subtle touch of sweetness.

How To Make Seaweed Pasta

This seaweed pasta with vegan scallops comes together with just a few thoughtful steps, and each one plays a role in building flavor and texture. Once the butter is blended, it’s mostly about timing—cooking the pasta, searing the mushrooms, and bringing everything together while it’s still warm and silky. For full recipe details, scroll to the end of this post!

• Step 1: Soak the mushrooms – A quick soak softens the king oyster stems, giving them a more tender bite and helping them sear up like scallops.
• Step 2: Make the seaweed butter – Blend softened cultured vegan butter with ground ochazuke wakame and matcha powder. The matcha adds earthiness, while the butter ties everything together with rich umami flavor.
• Step 3: Cook the pasta – Use spaghetti or your favorite slurpable noodle. You’ll want it just al dente so it holds up to the butter.
• Step 4: Sear the scallops – Dry the mushroom rounds well, then sear until golden and crisp at the edges.
• Step 5: Toss and serve – Toss the warm pasta with the seaweed butter, top with scallops, and finish with sesame seeds. Let it sit for a few minutes before serving so the flavors have time to settle in.

Creative Ways To Use Leftover Seaweed-Matcha Butter

This umami-packed butter deserves more than one moment. If you have a little left after making your seaweed pasta, here are a few easy, delicious ways to give other dishes a quick upgrade:

• Spread it on warm focaccia (especially this easy homemade version): Soft, salty, savory—chef’s kiss.
• Melt it into steamed rice: comfort food with a little oceanic depth.
• Toss it with roasted potatoes or asparagus: it clings beautifully to crispy edges.
• Swirl into vegan ramen: just a spoonful adds richness and a subtle green edge.
• Use as a finishing butter for noodles: soba, udon, spaghetti, you name it.
• Add to mushrooms or tofu: sear them first, then let the butter do its thing.
• Or keep it simple: spread it on toast, swirl it into a grain bowl, or use it as the secret layer on your next avocado toast.

FAQs

More Umami-Rich Noodle and Pasta Recipes to Try

• White Wine Sauce For Pasta
• Spicy Noodles Recipe with Crispy Tofu
• Vegan French Onion Ramen Noodle Soup
• Easy Soba Noodles Recipe

If you try this seaweed pasta recipe, please leave a comment and star rating below. Your feedback helps others find my content and makes my day!

This post was first published in 2016. The recipe is the same, but the writing is updated to provide clarity and helpful tips.